Transmission:Automatic Maintenance: FAQ Home Transmission Service

Transmission:Automatic Maintenance: FAQ Home Transmission Service
Transmission. Automatic AW70 and ZF
FAQ Home
Volvo Maintenance FAQ for 7xx/9xx/90 Cars
Transmission Service
In-Line Filters
7XX/940 Fluid Flush
A/T Fluid Needs Changing; Late or Poor Shift Quality
ZF22 Transmission Fluid Drain
Transmission Mount Replacement
AW-70-71 Transmission Life?
Transmission Line Crack Prevention
Transmission Model Information
Non-turbo Transmission in Turbo Car?
Stripped Trans Drain Plug
Removing Oil Pan
Fill Tube Removal
Kick-Down Cable Adjustment
Kick-Down Cable Replacement
Park-Reverse Lockout Button Repair
Transmission Not Shifting Out of Park
Reverse Lights Not Working: Backup Light/Neutral Safety
Automatic Shifter is Loose
Removing Shifter Knob and Overdrive Switch
Shift Indicator Lamp Replacement
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Transmission. Automatic AW70 and ZF
Shifter Detent Button Pops Up
Auto Tranny Refuses to Reverse: Mount Replacement
Transmission Output Shaft Bushing
Seal Leakage in AW70L Transmission
AW-70/71 Hard Shifts
Overdrive Relay and Function:
AW-70/71 Overdrive Problems: Relay, Switch
AW 70/71 Overdrive Problems: Wiring to Solenoid, Solenoid
Overdrive Removal
Lockup Torque Converter Function for Turbos?
AW7X Diagnostic Notes
ZF22 Damage in Park During Smog Test
ZF22 Fails; Swap for AW?
See the FAQ file
Transmission Removal:
Removing the Transmission
Bellhousing Bolt Removal
Torque Converter Alignment on Transmission Reinstallation
Rebuild Information:
Rebuild or Replace?
Transmission Rebuilding Instructions: Valve Body and
Complete Transmission
AW Transmission Parts and Rebuild Technical Help
Note: This file describes generic procedures and those specific to AW70 and
ZF series transmissions found in Volvo 7XX and 940 four-cylinder and PRV6 cars. For information about the 960/90 series AW-30 electronic
transmissions see the separate FAQ file.
Transmission Service Procedures .
Checking the Fluid Level. To check the transmission fluid level:
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Transmission. Automatic AW70 and ZF
The engine and transmission must be hot (so drive the car for 20 minutes or
The car must be parked on level ground with the handbrake on.
The engine must be on.
Start in P, then cycle through all the gears, ending up in P.
Then check the fluid level at the yellow dipstick. Reinsert the dipstick with the
notches toward the rear to avoid jamming it in the tube.
Checking Level When Fluid Is Cold. [Ken C] I've found that when I have the ATF
level correct (based on a warmed up transmission and the proper dipstick scale for
the temperature), there is also a way to reliably confirm proper fluid level when the
engine is stone cold and not running....e.g., after you've let the car sit overnight.
On the dipstick, above the plastic part that has the two temperature-specific scales,
there is a little rectangular notch on the metal portion. Assuming the fluid level is
correct, and the car is stone cold and you haven't started the engine yet, if you
withdraw the dipstick and wipe it off and then reinsert it, then upon withdrawing it
for this second time the fluid level should be on that notch. This does NOT work if
you just withdraw the dipstick and look at it -- you MUST withdraw it, wipe it off,
and then reinsert it before withdrawing again to read the level.
Service Procedures. [Inquiry] I am considering doing the 20k transmission
service. What do I need to be aware of?
[Editor] Easy: just unscrew the tranny pan drain bolt, drain, and refill with the
same quantity to the correct mark on the dipstick. You will need a funnel with a
long, thin neck to fit into the drain tube, and a drain pan. Use a socket on a
breaker bar (12 inches or longer) to break free the pan bolt, which may have a
little corrosion. Be gentle putting it back.
[Response: Chris Herbst] Volvo no longer recommends dropping the pan and
cleaning the screen on the AW70 as a matter of routine maintenance, even though
there is a strainer in the transmission. Neither it nor the pan need to be cleaned
unless major problems have arisen. This is from a recent Volvo Tech Service
Bulletin that dropped the recommendation, still found in most owner's manuals. You
do still need to drain and refill the pan regularly, though. [Editor] Many owners
highly recommend a fluid flush on a periodic basis, say every 60-80k miles. This
removes all residual dirt in the fluid.
Drain Plug. Watch out putting the transmission drain plug back in: recommended
torque is only 13-17 ft-lb in this soft pan. . The pan is very soft and I stripped the
last one that I did. Also use a new aluminum washer if possible. Bolt size is 10mm
by 1.50mm thread pitch.
Fluid Specifications and Drain Intervals. Use Dexron fluid in your AW or ZF
transmission. The latest Dexron Spec is III-H and it is all backward compatible to
the Dexron II or III listed in your owners manual. Even better: buy a synthetic fluid
such as Mobil 1. In the Lubrizol knowledge Base site at, they note
that two European commercial vehicle automatic transmission makers have posted
specs for mineral oil versus Group III hydrocracked and full synthetic automatic
transmission fluid lifetimes:
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Transmission. Automatic AW70 and ZF
Transmission Drain
Drain Interval
using Group
using Mineral III Synthetic
Oil Fluid
using Full
60k km/ 40k
60k km/40k
120k km/80k
30k km/20k
60k km/40k
120k km/80k
This is an indication of the value of synthetics in normal use. Mobil 1 ATF is a full
synthetic meeting Dexron III specs. Castrol Syntec is a Group III hydrocracked
fluid meeting Dexron III specs.
Safety While Working on Transmission. [Editor] Note that you can accidentally
shift your transmission while working around the linkage beneath. To be safe, don't
rely on "park": use jack stands and chocks to hold the car secure.
Any Bands to Adjust? [Inquiry:] I recently acquired a Volvo with an AW-70 in
good condition from my brother-in-law. I am planning to flush the ATF and replace
the filter in the near future. My friend suggested adjusting the bands while I have
pan off. Is this a reasonable thing to do? Does the AW70 even have adjustable
[Response: Abe Crombie] The AW55/70/71/72 and BW55 don't have bands. These
gearboxes use friction discs as brakes. Disc brakes don't require (nor is there any
way for) adjustment.
In-Line Filters. I've had one for a year and due for a replacement and surgery
next year. But my unit is made by Tekonsha (#4350A.) It is call MagFilter and
goes in the A/T return line. In addition it has a very strong magnet ring inside, you
stick a nail to the plastic cover and it will hold it. Should be replaced every 15K to
20K mi. and it's about $28Cdn. I've been running with this setup in -36F (-38C) no
problems. It filters down to 30 microns. For more info call Tekonsha 800-325-5860
(for your local distributor)
[Note: IPD now sells this filter for both A/T and P/S line applications; Wix sells the
same unit under their label.] After I changed it I opened the used one. I found that
the magnet inside was foul with metallic particles (it looked like grease, because
the metal dust was mixed with ATF)
Return line: The top line is the return line. You can check it by connecting a hose
to the end from radiator (disconnect the + wire on the ignition coil) and try to start
the car, you'll see ATF coming out of the line on radiator end. [Another note:]
Hurst now makes a filter unit that splices into the transmission fluid lines. It uses a
Fram oil filter as the filtering element. [Note from Jim Bowers] Hayden makes a
barbed fitting (#390) that connects to the radiator fitting and allows the hose to be
slipped onto the barb.
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Transmission. Automatic AW70 and ZF
7XX/940 Fluid Flush.
[Editor] If your car has sluggish shifting, especially when cold, or you would like to
remove all dirt and old fluid from your transmission, consider a complete fluid flush
instead of just draining and refilling the pan. "But my mechanic told me if I
flush the old, brown fluid, the transmission will fail! He won't touch it."
[Robert Ludwick/Kane Leung] Sadly, you don't have to pass an IQ test to be a
mechanic ( i.e. Bubba taught me this way an' that's how ah do it! ) But another
reason why shops say this is liability. Brown fluid means the tranny is has suffered
wear from neglect. They change the fluid for $50, and say one week later, your
tranny dies ... would you blame yourself for not taking care of it sooner, or the
shop because they were the last ones to do anything with it? Flush it anyway: it
works. Caution: If you have a ZF transmission, see below.
I recently changed the trans. fluid in our '92 940 using the cooler line disconnect
technique. Here is the easiest way to do it:
Obtain either IPD's transmission flush hose or a clear vinyl or plastic tube (3/8
inch I.D.) about eight feet long, three or four gallon milk jugs calibrated with a
permanent marker in quarts, and a transmission fill funnel with a long, thin
neck. Have at least your tranny capacity (approx 9 qts.) in new fluid on hand.
3/8vinyl hose is a tight fit (heat it in water to get it on); 1/2 inch I.D. will
require a clamp.
Buy 12 quarts of new fluid. Highly recommended: synthetic such as Mobil 1
Synthetic ATF.
Remove the transmission dipstick with the yellow top and put the tip of the
funnel into the filler pipe. Press down firmly on the funnel so that it stays in
place. If need be, use some wire to secure the funnel so that it doesn't come
out or fall over.
Drain all the oil from the transmission drain pan (2-3.5 qts depending on
model) and reinstall the pan bolt. Do not overtighten.
Refill the same amount (2-3.5qts depending on how much you drained out)
into the filler tube.
The transmission cooler return line is the top line entering the top fitting at the
radiator. Using two wrenches (one as a counterhold wrench so you do not
crack the fitting at the top of the radiator), remove this cooler line.
Penetrating oil can help loosen threads. Pull back gently on the cooler line to
separate it from the radiator. Push the transmission fluid line slightly aside
(use a cable tie to hold it, if necessary).
Connect the clear plastic hose to the radiator fitting by pressing it on the
thread, lubricating with ATF as needed. Fish it through over or through the
grill and into to a gallon milk jug on the ground. The disconnected return line
does not need to be plugged.
Turn on the engine. Fluid will start draining out of the tube into the jug. The
fluid does not drain out all that fast - ~25 seconds for 2 qts - and stops when
you stop the engine.
Watch the fill rate on the side of the marked jug and have a friend refill at the
same rate into the filler tube. [Editor's Note: have a friend engage parking
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Transmission. Automatic AW70 and ZF
brake, apply the main brake, and place the transmission in drive for a minute
to flush out other parts of the valve body and torque converter.]
After approximately nine quarts, you will notice fresh fluid flowing out of the
hose. Stop here.
Button things up (do not overtighten the cooler line fitting), check final level,
check for leaks, etc.
Everything worked very well - the only pitfall was that I ended up overfilling the
trans. a bit (~3/4 qt) - I think I must have been a little off every time I estimated
I had drained 2 qts. So finally I had to pump all that out of the filler tube while
checking the level - a bit of a hassle but not too bad. [Tip: if you overfill, just
unscrew the pan bolt slightly and hold it while the fluid drips out to the quantity
required. Messy but easy. Or, loosen the cooling line again and pump enough out
through that. Or, use a suction pump and a vinyl hose and suck it out the fill tube.]
Flush By Draining the Torque Converter? [Frank] Some Euro indy mechanics
have suggested that a better flush is achieved by first draining the torque
converter. Not true: this creates a large air gap and forces the tranny to run dry
while it refills. The Volvo OEM flush procedure is through the cooler lines as noted
A/T Fluid Needs Changing; Late or Poor Shift Quality.
Delayed Transmission Engagement When Shifting into Gear:
[Inquiry:] The drive gear engages late when shifting from P to D in my auto
[Response: Marc] The problem you describe can be attributed to either a low level
of transmission fluid or a stuck valve body. If the fluid is low in the torque
converter, it will take additional time to transfer the engine power to the
transmission, as the power is transmitted through a fluid by spinning up a plate
with fins on one side and the fluid spinning up a secondary plate with fins on the
other (thus keeping fast changes in the engine power output from damaging the
I would recommend that, if you have not recently (within the last 6 months)
changed the transmission fluid and transmission filter, you have this done. In my
area, the change runs as low as $49.99 US, including parts & labor. If you have the
Haynes manual for your car, take it with you if go to anyone other than the dealer,
as the fluid may have to be drained in a non-standard way via a transmission fluid
cooler return pipe (non-standard compared to other brands of vehicle). This service
will also clear up most sticky valve bodies, as the new fluid reliquifies old gummy
deposits...[Editor's note: see also Fluid Flush]
Late or Poor Shift Quality While in Gear:
[Symptoms:] Late or poor shift quality.
[Response 1:] Since this is an unknown as to when the transmission was serviced I
would recommend a power flush. Wynn's/Kendall has a machine that connects to
the line to the cooler. Then they add a detergent and run the car for about 20
minutes with it off the floor and in different gears. Then they go from a
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Transmission. Automatic AW70 and ZF
recirculation mode to a change mode and add new fluid while discarding the old.
This gives a full change including the torque converter. It will cost from $60 to $95
but I think it is well worth it about every 100000 miles with normal change in
between. I think both my ZF and AW worked better and smoother afterwards. Call
around and you should be able to find some shop that does a power flush.
[Response 2:] How dirty was the fluid was when the transmission was finally
serviced? Your transmission has no bands, just clutches. When pressures are right
for a shift, fluid pressure is directed to the clutch(es) that is/are to lock up. If there
is a lot of clearance due to wear in the clutch packs, you usually get a delayed and
hard shift. If the valve body has a problem, it could cause reduced pressure to go
to the clutch pack, causing a slip as it shifts. The most common problem is
governor pressure loss due to a worn output shaft bearing. Even after the output
shaft bushing is replaced, the problem could still exist because while the bushing
was bad, excessive wear to the transmission case where the shaft goes through, is
common. A pressure test will in most cases will pinpoint the problem. This is reason
# 71 for servicing the transmission at normal intervals. Every 20,000 miles is
recommended. It's pressure test time.
Intermittent Shift Failure: Clogged Filter
[Inquiry:] After starting, everything goes well, the transmission shifts, but in a
short while, suddenly, the transmission becomes disconnected, losing traction;
moving, I accelerate and the motor increases revolutions but the car behaves as
though it were in neutral. I must stop the motor, wait a moment and repeat the
operation. While the problem is occurring, if I accelerate in neutral I hear a slight
buzzing noise of gears even though the transmission has not engaged. The oil is
new. I changed the kickdown cable.
[Response: Abe Crombie] The things you list sound like a stopped up filter inside
transmission pan. Did the pan get removed and the filter inspected? The filter is a
fine metal mesh strainer and can be cleaned in most cases. I didn't read your
previous post of a month ago so I do not know how this started but using shop
clothes to wipe off things inside transmission or to wipe the pan when it is off, can
introduce lint that the transmission filter will catch when it is running. The debris
on filter then starves the transmission pump for oil. The transmission pump will
whine when operating with excessive vacuum on its inlet due to a plugged filter.
When you stop and shut down engine, the lint falls off the filter and it will work
again for a period of time until the lint is sucked up onto filter once again.
ZF22 Transmission
Fluid Drain. [Procedure:] ZF 4HP22 Transmission Fluid Change. This is passed
along for the 740 owners with this transmission. I have the same transmission on
my Peugeot and found out that if you leave the car for a few days on with the front
end on jack stands, the fluid in the converter will slowly drip out. This way you can
get an almost complete drain before refilling. [Tip] HEAT is the biggest enemy of
every tranny (especially in automatics). I've got a ZF on my 740 and synthetic ATF
dropped the tranny temperature from 92C to 60C (driving in a summer for about
40min. in a city). I've measured the temp. on the tranny metal line, the temp. of
the fluid itself is most likely higher.
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Transmission. Automatic AW70 and ZF
ZF22 Preventive Maintenance. [Fitz Fitzgerald] There are many people putting a
lot of miles on ZF transmissions, but the transmissions are more prone to failure
than the AW trannys. A few words of advice for preventive maintenance on ZFs:
1. Do not rev the engine in Park or Neutral: this will tear one of the forward
clutch packs to pieces.
2. Change the fluid at the specified intervals and be sure to remove and clean the
pan before the first fluid change. Performing a fluid flush without removing the
pan can break up some sediment in the bottom which will be sucked up into
the takeup and act like sand in the bearings and valve bodies. Feel free to
toss in a larger magnet before putting the pan back on.
3. Run synthetic trans fluid if you can afford it. Mobil 1 full-synthetic is worth the
improved longevity.
Transmission Mount Replacement.
[Editor] The rubber transmission mount will
compress over time and need replacement.
To do this, support the front of the car on
jackstands. Place a jack under the
transmission pan with a board to distribute
force and jack up enough to support the
transmission. Remove the rear support cross
member and change the transmission mount,
reinstalling in reverse order. Welded Frame
Nut Breaks Off. If one of the frame nuts
breaks off, see this link for a repair using a
serrated flange nut.
AW-70/71 Transmission Life? [Inquiry:] Any thoughts out there on the life
expectancy of an AW70 tranny. I've got a 745 with 145K and it seems strong. I
flush the fluid every summer. I know some think this is not good, but it seems to
work. Are the AW70's rebuildable or do you just replace them?
[Response 1:] I had a minor problem with this tranny (worn check valve in the
valve body, which caused it to shift hard between 1st and 2nd gear). When it was
fixed, I also asked about the tranny in general, and I was told that these units
usually require a rebuild at about 350 000 kilometers, or more than 200 000 miles.
And only the clutch and brake packs need to be replaced, usually all the bearings
are still OK.
[Response 2:] They can go 250 K. They can be rebuilt, that box is shared with
several Toyota rear drive 4 cyl models in the early to late 80's.
Transmission Line Crack Prevention. [Tip from Tony P] My lines actually rubbed
together long enough to cause a leak. I removed the clips and installed a
compression fitting to repair the leak. Then I cut some sections of rubber hose,
slicing them lengthwise so that I could slip them over the transmission line. Then,
using a zip tie or tie wraps as they are called, I secured the rubber hose around the
transmission lines to stop chaffing.
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Transmission. Automatic AW70 and ZF
Transmission Model Information. See the table in the Model Information file.
Non-Turbo Transmission in Turbo Car? Can the non turbo tranny be put into a
turbo car? [Dale Walmsley] ] I'm running an AW71L in my 740T and would not
recommend it. The L is not designed to shift like the standard AW71 under the full
power of a turbo engine. [John Martin] I believe consensus here and on turbobricks
is that you should stick to the AW71 used in the Turbo cars. It has more robust
internals than the AW70 (used on non-turbo 240) and AW71L (used on non-turbo
740/940). I found an equal number of Turbo and non-turbo 940's out in the yards
when I was tranny-shopping a few months ago. The trick is finding a wrecked car.
And you should absolutely drop the pan and check for chunks first. 1993-1995 will
have the roller-bearing tailshafts, which is a nice improvement.
[Fitz Fitzgerald] A 700 series Volvo Turbo car would have come fitted with an AW71 transmission (non-lockup). The 71 series are a bit stronger mechanically
speaking, and there are some differences in the valve body to help it respond
better to the torque and HP curves of a turbo engine. US market Turbos (and quite
possibly the rest of the world too) never received L series automatic transmissions.
The Turbocharger's response curve is directly dependant on the engine RPMs and if
you had the lockup engaged, the engine RPMs are now directly coupled to the
vehicle speed. Much of the extra torque and horsepower that a turbocharger can
provide requires that the engine can rapidly climb the RPMs. Aisin Warner lockup
trannies aren't well known for the ability to quickly disengage the Lockup TC,
unless you drop down to 3rd gear in which case the response is almost
To convert any AW70 equipped car to AW70L, you must swap both the
transmission and the torque converter, since the valve body controls and additional
converter clutch are different from the non-lockup versions. The torqure converter
has the lockup clutch inside it, and the transmission has a special valve body and
hydraulic actuactor that enables/disables the clutch. You can't just swap the valve
body either, you need to swap the entire tranny. If you are looking to install an L
series tranny in a turbo equipped car, they did make an AW-71L series tranny and
it can be found many of the 940 non-turbo wagons. The US spec turbo cars only
received the AW-71 during their entire production run. This should be "plug and
play" but make sure your detent/kickdown cable is properly adjusted after
installation. If you tighten this cable, the transmission will shift at higher RPMs, if
you loosen the cable, it will shift at lower RPMs (this will effect every shift point,
not just your 3-to-4 shift). Find the spot that's best for your driving habits.
[Abe Crombie] A US market spec Volvo rear wheel drive turbo doesn't have a
locking converter. If yours has a locking converter the ID plate on driver's side of
gearbox will read 03-71L or possibly 03-70L if someone has changed it. The lockup
control in either case is a function of it being in 4th gear and governor pressure
reaching approx 50 psi. A lock/unlock at threshold of locking speed can be caused
by a worn bushing in tailhousing allowing the gov. pressure to fluctuate. This can
be checked by attaching a trans press. gauge and reading the gov. pressure at
speeds around 45-55 mph to see if the pressure is stable as speed is brought that
range gradually.
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Transmission. Automatic AW70 and ZF
[Gene Stevens] The only AW71L gearboxes available in NA behind the B230F (not
turbo) do NOT have the same valving or number of clutch plates as the turbo
version. Same for the AW70/70L used before 1992. It is a light duty version and
will not live long behind a turbo engine, regardless of the "71" designation. The
reason a lockup converter was used with turbo in Europe, but not NA, is that the
higher 120-140 kmh highway speed allowed the turbo to stay in boost range but
US/Canada 80-90 kmh speed lowered engine (and turbo) speed too much for good
Stripped Trans Drain Plug. [Inquiry:] Did a routine fluid change. Detected a slow
leak from the plug area a few days later. Removed plug. Threads were stripped.
Purchased new plug. Unable to get a tight fit since threads in pan probably also be
damaged. No leakage yet, but I fear that plug may eventually loosen, I'll lose fluid
and destroy the tranny. (so much for preventative maintenance.) Replacing the
fluid pan seems to be the obvious solution. I would appreciate any suggestions on
a good source for a pan, or alternative solutions to the problem
[Response: Simon Eng] No need to replace the pan. There is available a kit
specially designed for this purpose. My mechanic has several sets and he let me
borrowed one of the sets. First check what size is the plug. Let say it is 12 mm by
1.5 mm. The kit for this size has a drill bit and a tap with 14 mm by 1.5 mm. You
drill the drain hole with this drill bit, then thread the hole with the tap. There is an
insert that has 14 mm by 1.5 mm on the outside and 12 mm by 1.5 on the inside.
Screw this insert intp the hole and use the supplied expander to expand the insert
and to position it on the threaded hole. Now the insert is firmly anchored. If the old
drain plug is still in good shape, reuse it; otherwise get a new plug.
[Response 2: Kane] Naturally, in upsizing the plug, you'll need to tap new threads
for the hole too. Drill the hole smooth, then tap - you don't want the new threads
crossing the old ones. You may also try chasing the existing hole with the exact tap
size and thread count as the current plug. Sometimes this is all that's necessary to
clean the remnants of the old plug and whatever else is stuck in the threads. This
assuming that you do have a tap and die set. Otherwise, plucking a pan from the
junkyard may be the best bet.
Removing Oil Pan. [Editor/Jay Simkin] In a pre-1990 700 series, removing the
pan is simple: just remove all the 10mm bolts and drop the pan. In a 1990+
700/900 car with the intermediate exhaust bracket mounted to the rear
transmission housing, removing the pan gasket is a major undertaking because the
bracket interferes with both the bolts and the pan itself. Here is how to do it if you
1. Drain the pan and loosen the fill tube fixing nut (24mm nut and 30mm
counterhold on the pan). If this is stuck, see below.
2. Support the front of the transmission with a jack, using a block of wood on the
casting just ahead of the pan. The block of wood is needed to go on top of the
jack to allow the trans to be lifted, so the trans support can be removed. That
block of wood cannot be more than 1 1/2" wide, or it will interfere with access
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Transmission. Automatic AW70 and ZF
to the pan bolts. Before you begin, make sure you have clearance to remove
the pan and its bolts.
Remove the rear transmission cross member support that holds up the output
housing. There are five bolts that hold the trans support: two at either end,
and one in the middle.This is a great time to replace the very inexpensive
transmission mount.
Remove the casting that mounts between the transmission rubber mount and
the rear output housing. This loosens the exhaust pipe bracket.
Take a hard look at the exhaust pipe bracket and note how it interferes with
the two rear pan bolts even with a 1/4 inch drive 10mm socket. To improve
future access to the pan bolts, remove the bracket. On the end closest to the
driver's side of the car, removing 1/4" of metal (starting on the part of the
bracket closest to the ground, and going upwards, around the curve in the
bracket, and about 1/4" past the curve) will allow unimpeded access to the
trans pan bolt. However, on the end closed to the passenger's side of the car,
the bracket runs directly over the head of trans pan bolt. I did pare the
bracket back, up to the reinforcing bend. However, no amount of metal
removed from the bracket allows unimpeded access to the trans pan bolt. The
only thing that will work is bending the bracket, so that there's clearance for a
socket to be inserted, between the bracket and the trans pan wall.
Remove all the 10mm pan bolts and drop the pan. Clean the pan and screen if
needed. [Fitz Fitzgerald] The stock magnet that's in the pan is undersized for
the job, so I throw in three more of the same size, or a large ring magnet
that's typical of the General Motors T-125 trannys. This helps keep any future
sediment in the pan.
Make sure the pan sealing surface is flat and not dimpled, using light taps
from a ball peen hammer to correct any dimples. Replace the gasket (no
sealer or adhesive!) and install the pan. If needed, use thin sewing thread in
four or five places to tie the gasket in place. Torque all 10mm bolts to 4-5 ftlb.
Reinstall the exhaust bracket and the rear cross member.
Reinstall the fill tube nut, making sure you use antiseize to prevent corrosion
and seizure.
Fill Tube Removal. Removal. [Editor] What should be a simple task while
removing the pan often turns into a major nightmare because the fill tube nut
seizes up. If this happens to you, try to remove the nut but realize that you can
pull the pan with the fill tube still installed:
Use plenty of PBlaster all over the nut and let it soak for a day.
Use a quality open-end wrench and adjustable wrench as backup. No Chinese
tools here. Under no circumstances should you not use a backup wrench, as
you will tear the transmission pan.
[Tip from Glen] You need to hold
the big nut steady and try to turn
the smaller nut. The big nut is
actually not a nut at all: it is a
threaded flange with hex sides. It
does not turn. If it turns, you
have ruined the pan. I place a
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relatively large crescent wrench
(open end adjustable wrench) on
the filler tube flange nut, with the
end of the wrench pointed toward
the rear of the car. If you orient
the wrench jaws correctly, you
can brace its handle on the flange of the transmission pan (the flange where
the gasket is located). It' a tight fit, but it works. I then use a smaller
crescent wrench to turn the small nut ccw. The first wrench prevents
excessive torque from being applied to the filler tube flange where it enters
pan. I sometimes need to use a breaker bar (steel pipe with one end flattened
to fit over the wrench handle) with the small wrench to generate some extra
Use heat from a hot air gun or a torch (flammable! caution!) if needed.
See the photo for a tip from Tom F. to gain more leverage. "To remove the
filler tube, I wedged a 4X4 betwixt a crescent wrench and the frame then
used a small jack to encourage the filler tube nut to turn. It fought back all
the way. The last three turns took two of us pulling the wrench using a bar
through the combination wrench's closed end."
If you cannot remove the nut without destroying either nut or pan, you can
still pull the pan with the tube installed by removing the two starter bolts that
hold the fill tube. It is not essential to be able to remove the fill tube. If these
are seized, then you should call it a day and forget the entire procedure.
On reinstalling the fill tube, make sure you use antiseize to prevent this from
happening in the future.
Cutting the Tube. [Todd Brun] I could not remove my transmission pan due to the
stubborn flange nut of the filler tube connection at the pan. Instead, I cut the fill
tube and joined it with a compression fitting. I felt that using a tubing compression
fitting would be more secure than mere rubber hose and clamps. The tube is 18
mm, but this happens to be almost exactly 5/8 inch. I used a 5/8 inch Parker
industrial union, Part Number 10-HBU-S. Cost = $US 8.60, not including tax. The
union went on easily. You must remove about 5/8 inch of the tubing to take the
place of the body of the union.
Kick-Down Cable Adjustment.
Function of Kickdown Cable. [Discussion from Abe Crombie] The kickdown cable
is used to regulate a pressure in the transmission valve body. This is called throttle
pressure. The throttle pressure is effectively a pressure that tells shift valves in
transmission how hard you are pushing the throttle and these shift valves now have
a contest to see if governor pressure or throttle pressure is going to win. This
pressure is also used to apply the clutches/brakes that engage a gear and the
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higher pressure goes along with higher engine power at higher throttle. Firmer
shifts are a result of higher throttle pressure. If throttle pressure wins the contest
the trans remains in lower gear, if governor pressure wins the trans upshifts.
Governor pressure is directly related to driveshaft, and thus road speed. If you
tighten cable you increase throttle pressure and the whole shift point/road speed
map goes higher. If you loosen cable the shift point map moves lower. The trans
throttle cable (kickdown cable) also depresses a valve if you (or the throttle spool)
pull the cable all the way out past that hard spot which is a detent to make you
aware of the actual kickdown feature. The kickdown valve increases the throttle
pressure drastically above the linear rate that you get from the rest of the throttle
pedal travel range and makes the gearbox goes to lowest possible gear allowed at
the road speed you are at when you activate it.
Adjustment of Cable. [Abe Crombie/Dave Stevens] First make sure the cable is
properly sitting in its groove in the throttle spindle. When properly adjusted, the
cable clamp should be 2" from the cable end when the thottle is wide open and
1/32"-1/16" (1 mm) from the cable end when the throttle is closed, i.e. almost
touching the rubber end cap. If someone has been playing with throttle body
adjustments (throttle stop screw or linkage rod length) then the throttle spindle
rest position may have changed and may be affecting kickdown cable adjustment.
The kickdown cable has no adjustment at the transmission end, it's fixed. All the
adjustment is done under the hood at the throttle spindle. To adjust, loosen the
13mm cable housing jam nuts until there's plenty of slack in the cable. Apply some
antiseize so the task is easier both now and in the future. Make sure you count the
number of flats on the nuts so you can return to the original position if needed.
Pluck the cable by lifting the open section, then let it snap back in. Listen carefully,
and you'll hear the cam that the cable is attached to in the automatic transmission
click up against its stop. You'll need a quiet environment for this to work. Try this
a few times, so you'll know the sound. Now adjust slack out of the cable, keep
testing by pulling and letting go of the cable, always listening for the click inside
the transmission. As you take more and more slack out, there will be a point where
you've tightened the cable just enough so the cam inside the transmission can no
longer click up against the stop, because the tightened cable won't let the cam go
back far enough. When you reach this point where you just stop hearing the cam
click against its stop, the cable is adjusted properly. [Dave Stevens] When properly
adjusted, you should not hear the pawl go thunk against its stop; the proper
adjustment is just past the point where it faintly did go thunk. You can adjust this
a little tighter or looser if desired, say by a few adjuster nut faces, to achieve
slightly more aggressive or slightly smoother shifting.
[Don Foster] Loosen the cable to soften the shifts, and shorten (or tighten) the
cable to cause the tranny to shift harder and at higher RPMs. Be sure to keep notes
of which way you adjust the cable and by how much so you can restore it to
original position if you're unhappy with the results. Loosening the cable means to
adjust the cable housing (outer sheath) so the inner core is looser around the
throttle spool. This means adjusting the housing (outer sheath) TOWARD the
throttle spool. This has the effect of providing a bit more slop in the core, which is
wrapped on the spool. Thus, it becomes looser. If you want to tighten the cable,
adjust the cable housing so it backs away from the throttle spool, effectively pulling
the core tighter. Normally you adjust in turns or flats. A flat is one flat on the hex
head where you fit the wrench, six per full turn. [Ernest Smith] I had a hard time
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hearing the pawl come to rest, I took pressure off the cable 3 flats at a time
(i.e., by bringing the sheath of the cable closer to the end of the cable itself.) After
I loosened the two 13mm nuts, I then snugged them back - held the metal portion
on the right side of the cable steady with some pliers while I backed off on the
right nut, then tightened the left. I did a total of 8 flats, 3,3, then 2 (testing in
between) ..and it is pretty close - works much, much better.
No More Adjustment Length Left? [Inquiry] At the maximum extension of my
kickdown cable, the car's not shifting as soon as it should. What can I do, now that
I've run out of adjustment length?
[Response: Justin] Check to see if the cable sheath has come out of the crimped
metal part at the end. On my car, the sheath pulled out of the metal ferrule at the
end of the cable. This had the effect of shortening the kickdown cable by about 2
inches and the car would not shift correctly no matter how far I adjusted it. While
you can try re-crimping it, the solution is likely to be a new cable.
Failure to Adjust Properly. [Dave Stevens] If you cannot get the cable adjusted
to hear the pawl thunk, there are a few possibilities. If the cable is starting to
wear, it may not be sliding freely enough to snap back quickly with enough force to
make the clunk -you could try working some ATF lubricant down into the cable if
that's the case. Also, if the cable is not the original kickdown cable it may not have
been installed properly. The cable sheath must be properly seated all the way down
into its recess (that's pretty hard to miss, but someone could theoretically have
later reefed on the cable enough to move it). The cable clamp (copper ferrule) may
well be mis-located on the cable. When a replacement kickdown cable is installed
the copper ferrule is loose and is clamped in place by the installer, preferably
AFTER proper kickdown adjustment. If not, it may have been clamped too close to
the cable end. In that case it's unlikely you'll be able to easily free it and you may
have to resort to removing it by carefully nipping the clamp away without
damaging the cable strands. The cable clamp is used to prevent the cable from
slipping too far down into the tranny and is also used as a crude adjustment
reference point. Other than that it's not really needed. A small blob of something
like JB-Weld would probably do just fine as a replacement if you have to remove
the original clamp. Another possibility is that there is gunk in the bottom of the
kickdown cam chamber preventing the pawl from striking back against metal. If
that's the case then a tranny fluid flush may be in order and the cable clamp should
be used as the adjustment reference with the above measurements.
Failure Modes of Kickdown Cable. [Chris Mooney] The kickdown cable can fail
due to corrosion or a break in the sheath at either end (usually due to leaning on it
while working on the engine from above). Dirt, dust, grime, sludge, wearing
through and fraying, all take their toll and cause extra resistance. The cable is
retracted by a fairly weak spring to prevent excessive resistance at the accelerator
pedal - the downside is that a bit of dirt or a cable housing that's worn through and
collapsing on itself will keep the cable from retracting smoothly. Replacing it is the
only sure fix. But try unhooking it, spray with PBlaster, and then pouring some ATF
oil down the cable into the cable housing, while you work it back and forth. It'll
help a bit. Add this to your regular lubrication routine to keep things loose.
[Gary Horneck] I took the cable end off the throttle linkage and taped a little foil
collar/funnel on the end. This way I was able to hold the cable upright and fill the
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funnel with tranny fluid. I filled the little funnel several times over a 2 hour period.
All that fluid went down the sheath and has freed up the cable. [Bruce Young] I
was able to free up a stuck cable by patiently working at it with pliers till some
back and forth movement was possible. At that point I took the cable and sheath
out of the pulley and adjuster bracket and began to apply ATF to the exposed
cable, so it ran down and seeped into the sheath. Periodically the ATF drip was
interrupted to repeat the range-of-motion exercise with pliers, and eventually (a
few hours) the cable was totally free to retract on its own and could be adjusted.
Kick-Down Cable Replacement.
Diagnosis. If either end of the cable is cracked, the ferrule is loose, the metal
strands under the plastic sheath cover have pulled loose from the ferrule, or the
cable is binding in the sheath, then it needs replacing.
Repair Procedure. [Tips from various and Nelson
Torres] Parts are about $100 - $75 for the
kickdown cable, $25 for tranny pan gasket and
filter. It's about an 1-1/2 hour job, very messy
though as you must drop the tranny pan. You kind
of need an assistant to help with the cable, and a
long pair of narrow vise-grip pliers. Basically :
Drain the transmission of fluid.
Unbolt the dipstick/filler tube from the
transmission sump (requires 24mm wrench
and 30mm counterhold wrench; may be very difficult and require a giant pipe
wrench). More fluid will run out. Placing a box with a plastic liner and filled
with kitty litter under the tranny will minimize the mess.
Unbolt and remove transmission pan (10mm bolts). More fluid will run out.
Unbolt and remove the transmission filter. More fluid will run out. You now
have access to the cable and tranny innards.
Have somebody fully extend the cable, this will rotate the internal valving
fully. Clamp onto the rotating valve (where the cable attaches) with the
narrow vise grips immobilizing the valving (it is spring loaded). With a second
set of narrow pliers remove the cable end from its recess in the valve
actuator. [Tip from Ian Billerwell] I recently replaced cable on my 89 745 with
AW72L and found a handy tool to rotate the pulley. A bit of coathanger wire 6
to 8"long with 90 deg. bend only 1/4". In my pulley there is hole in the side
near where the cable locates, I found it a cinch to rotate pulley. [Tip from
Bean] I tried needle nose pliers to squeeze two of the locking tabs together
but to no avail. Instead I put a medium sized screwdriver in the middle of the
plug (from below) and whacked it with a hammer. This released the plug with
no effort at all. [Tips from Nelson Torres] When you remove the tranny pan
you will see the cable and cam.Now pull the cable with needle nose pliers to
form a loop.This step very important because with the cable in a loop you can
hold the cam in the right position and then wedge a screwdriver in there to
hold it in place. I was then able to remove the cable by feeding the cable into
the cam. It finally unwound enough that I could grab it with the pliers and
finish the job.It helps to have a long thin screwdriver and an index finger.You
try to rotate the cam with your finger then wedge the screwdriver,then rotate
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the cam, then the screwdriver until you get the cam where you can hook up
the new cable.
Remove the cable & sheath - friction fit in transmission, bolt-on at throttle
Re-assembly is reverse of disassembly. Careful not to remove the vise grips
until the new cable sheath is seated in the tranny and the cable end is
attached to valving
You can use thin sewing thread to hold the pan gasket in place: just tie it in 4
or 5 places to keep it from moving around.
[More Tips from Don Foster] Replacing the cable is straightforward. If you have the
pan already off, swapping in a new cable should take only a few minutes. Look in
where the cable attaches, and you'll see a cam-like or pulley-like gizmo around
which the cable wraps. You can (carefully) turn this with a sharp tool or
screwdriver (it's spring loaded.) You'll be rotating it against it's return spring, and
as I recall it's a little tricky. Once rotated to the fully extended full throttle position,
stick a screwdriver in to wedge it and you should be able to pull the cable end free
of its hole. The old cable will disengage -- it has a round thingy at the end fitting
into a recess.
The tranny end of the cable housing friction-fits into the tranny housing. I'd clean
and blow-dry the outside area before removing the old cable. As I recall, you can
pop if out with a screwdriver -- and pop the new one in similarly. I used a touch of
synthetic grease on the O-ring-like seal.
Once installed, you install the upper end and adjust it so it just slackens when the
throttle's at idle. Also, you should be able to hear the tranny valve clunk slightly
when it slams back to idle. Install the small crimp around the cable core about 1/8"
upstream of the orange rubber gasket. This crimp is sorta important -- it prevents
excess cable from entering the tranny and keeps the cable in the pulley groove.
Park-Reverse Lockout Button Repair. [Inquiry] The other day on my 1990 740
GL w/auto trans, the little thumb button / reverse lockout, whatever, popped and
popped up.It looks like some kind of retaining ring or clip used to locate the rod. It
can now be completely removed and it is a bit stiffer to shift. I've been leaving it in
neutral and using the hand brake to park and wonder if it is a terribly involved job
to get down into the console to fix it.
[Response: John B] The thumb button can be replaced easily...get a new one and
pop it on. Make sure you get it right front to can be installed backwards
and feels funny. [Nik Abdullah] The button base that clicks onto the top of the
shifter shaft in my car had a crack. There is a spring underneath the button: don't
lose that. A new button can be had from the dealer and assembly is the reverse as
they say. You need to push hard down on the button so that it'll engage a groove
inside it's base. If not the button won't hold and likely to pop out again. [JohnB] If
the rod itself has come up, you're in a little bit of a problem. I went through a fix
on our 87 760T and the key is the spring steel roll ring that is used to hold the rod
to the bracket down in the guts of the shift selector. A nail won't work...bends and
the rod pops out. We tried several solutions and finally ended up replacing the
entire shifter assembly for about $250 in parts, including club discount. Good thing,
too, because the wire for the OD was dissolving and surprised the heck out of me it
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wasn't grounding and causing the OD to shift out randomly. The new shift selector
feels better than new, BTW. Easy to remove the entire shifter assembly, but make
sure you either mark the adjustments on the shifter rod to the trans and the stay
rod, or be prepared to readjust the linkage.
Transmission Not Shifting Out of Park
Transmission Linkage Maladjusted. Cars built prior to 1991 do not have shift lock
solenoids. If you are having a difficult time shifting out of park, check your
transmission linkage adjustment, the linkage bushings, or the park-reverse release
button mechanism on the top of the shifter.
Faulty Shift Lock Solenoid Mechanism. Beginning around 1991, 740/940 automatic
transmissions were equipped with a shift-lock solenoid that prevented shifting out
of park unless the driver presses the brake pedal. Starting around 1993, a
microswitch controls this solenoid. Replacing the microswitch requires that you lift
the shifter as noted below; replacing the shift lock solenoid requires that you
remove the shifter from the car.
Symptoms.[Inquiry] My transmission will not shift out of park when I step on the
[Response: Bob] Shift lock solenoid not releasing. Possible causes, brake light
switch, micro switch in shifter assembly, or bad solenoid. Micro switch most
common. Access the shifter by removing console; on the passenger side near
indicator is a small black switch with a metal lever. The switch is about 1 in. long
@1/2 in wide, mounted with a small round metal clip. There are two black wires.
You have to unbolt the shifter and lift up slightly to access switch, but don't have
to disconnect anything under car. Be careful removing switch retainer as its easy to
break the small plastic post the switch mounts to. To test, short the two wires
together with key on and brake pedal
pressed. If it now comes out of park,
replace or bypass the switch.
Repair Notes. [Editor] This is a
known frequent-failure item, in part
because the ridiculous design of the
switch mounts on two small plastic pins with push fasteners to hold it on. The
switch itself does not last long. If you replace yours, install the new one in such a
way that a replacement can be easily installed.
Shift Lock Microswitch Replacement. [Tips from Tom Irwin] Lately, my AT has
been failing to allow a shift out of PARK about 90% of the time. I have to press the
Shiftlock override to get going. This car was serviced in 1996 under the recall
campaign to replace a defective shiftlock microswitch inside the shifter console. The
A-hah! went off in my head because I have been substantially underwhelmed about
the abilities of the dealership where I purchased the car. I got out the books and
went looking for trouble. To get at this thing, it is advisible to remove the following
parts, roughly in this order [applies to both 960 and 940 as noted]:
[960 Only:] Both Right and left knee bolster covers. Two screws on the left
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and one on the right cleverly concealed behind a snap lock cover. Un-buckle
and un-snap them the rest of the way. NOTE how they slide out of a plastic
extruded support molded in to the kick panels. Dum-Dum's at Volvo dealer
had jammed them back in, over and under these supports and tweaked them
all to hell. It took awhile to get 'em back in right. Had to let them bake in the
sun for a while to get a little pliable.
Take out the ashtrays and fuse box cover (940) in the front.
Pull up on your E-Brake. Slip a finger under the screw concealment panel and
wiggle it side to side till it pops up.
Remove two screws that secure left and right side of center console shifter
and emergency brake cover to the transmission tunnel.
[960 Only:] Remove the two screws holding your armrest/cupholder to the
junk box. NOTE: If you have ever dropped that armrest or otherwise treated it
rough, you will see cracks in the hinge guides that support your release latch
on the armrest/cupholder/junk box cover. Now is an excellent time to put a
small drop of super glue (NOT the gel stuff) right there. It will wick in to the
cracks and reinforce them.
Empty ALL your junk out of the junk box. Use a small slotted screwdriver to
lift out the screw concealment panel in the bottom of the junk box. It is tough
to see, use a flashlight. Remove two screws from the bottom of the junk box.
Lift up whole center console assembly from the rear, a few inches. Put two
fingers under the wood-look trim around the rear seat ashtray bezel. Push up
on two tabs and lift ashtray bezel up and away. NOTE: The little light bulb
that is supposed to light up your rear seat area and the inside of your junk
box usually is dead, now is a great time to replace it.
Lift whole center console up and away and remove it from the car. NOTE: This
too is a good time to scrub down the plastic mold of the center console, scrape
off old food, spilled drinks, whatever. You will no doubt find a couple of dollars
down there between the seats. Now you can vacuum out the seat tracks
where heretofore you could not get down there with the skinniest of
Disconnect seat heater wiring switch and lamp connectors and remove the
emergency brake and shifter cover. You will have to maneuver it around the
brake and shifter. If the seat heater switch lamp is out, now is the time to
replace it.
[960:] Disconnect the wiring harness that goes to the shifter, (960 Left side,
940 right) Re-route the harness end around so you have enough slack to raise
the shifter a bit.
Remove 4-10mm bolts that secure shifter. Raise shifter up an inch or two. Lift
up the dust flap on left side of shifter.
There it is, a snap-acting microswitch. If you are in PARK, it should be pushed
closed by the metal pin moving with the shifter handle. The switch mounts on
two fragile plastic pin extrusions from the shifter body. Two spring type
retainers are supposed to be pushed on to the pins after switch is installed
over them. In my case, one spring lock retainer had fallen off of the pin and
was laying in the soundproofing insulation, the other one was working loose
from the other pin.
I took off the switch, cleaned it adjusted the lever, and tested it. Then I
reinstalled it and pushed the lock retainers on really tight. [Editor: if you are
going to take the whole thing apart, you might want to install a new switch.
Cost is around $20. Replacements come with crimp connectors; anticipating
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future repairs, I used removable spade connectors insulated with heatshrink
tubing. DON'T drop the small push nut fasteners when installing them: use
sticky adhesive or the like on your fingers]
Put everything back in reverse order and it works every time now. [Editor:
lifespan of these things seems like around three years.]
Shift-lock Solenoid Replacement. The shift-lock system is a safety feature
designed to make sure your foot is on the brake before shifting out of Park. It is
activated by a solenoid in the shifter assembly. This solenoid, controlled by either
the brake light switch (1992) or the shifter microswitch (1993+) is buried deep at
the bottom of the shifter on the right side. If it fails, the repair kit (including the
solenoid and all associated plastic parts) costs $200+ so give some thought as to
whether you want to keep this safety feature or not. If not, see below to disable it.
If you do want to replace it, remove the shifter assembly as noted below.
Disabling the Entire Park-Shift-Lock System:
[Editor] Cursed 940 park-shift-lock microswitch! My 95 has been through two of
these in twelve months. They are a small pain to replace, but bearable until the
park-lock solenoid died. I have been parking in N and pulling the emergency brake
handle to hold the car: it won't go into P. Worse, this solenoid kit (p/n 3549869
depending on year) costs over $200, must be ordered from Volvo Sweden, and is
buried inside the shifter assembly. Worst of all, it is a positive locking device, so if
it fails, or if the microswitch fails, it locks the car either into or out of park. I
prepared to remove the entire idiot-proof locking assembly and be done with this
annoyance. Here's how to do it by first removing the shifter assembly:
Removing and Disassembling the Shifter Assembly:
1. Remove the center console between the seats, along with the tray containing
the seat heater switches and the ashtray. Remove the ashtray and fuse panel
cover. Lift one side of the bolster horizontal brace at the front of the shifter
box. If it is too tight, just barely loosen one Torx screw on the horizontal brace
right behind the fuse panel, pull the bolster panel inward, and lift this brace
up. Use a T-25 bit taped into a small wrench to access this screw.
2. Drive the front of the car up on ramps. From beneath, unhook the locking
circlip on the transmission rod-to-shifter connection with a narrow screwdriver
along with the securing washer. It is probably rusted so use PBlaster. Pull the
transmission rod away from the shifter arm. [Note: if you need to loosen the
bolts, MARK the position of the bolt shaft on the transmission rod with a chisel
so you do not affect the adjustment on reassembly.] Disconnect the overdrive
solenoid wire and cut any zipties impeding removal. If your shifter has two
arms, do both. [Parts Note: this is a great time to replace the rubber bushings
(p/n 381704) and rusted circlips ( p/n 951669)].
3. If so equipped, tie off the key-removal cable at the front of the shifter and pull
the ball out of the catch.
4. Cover the sides of the seats with towels. Pull the shifter assembly up and
maneuver it so that you can work on it without pulling the wires. If you need
more access or need to remove the shifter, disconnect the wiring connectors.
5. 1993+ 940 Shifters with Plastic Arms. remove the rubber seals on both sides
of the shifter box. Unhook the locking palnut on the lever side. Pull the plastic
lever arm off. Note that it is parallel with the shifter knob. On the side
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opposite the arm, use a punch to drive out the center pin. Pull the shifter out
of the box, being careful about the wiring.
Earlier 740/940 Shifters with Two Arms. A pain taking this apart due to poor
design. Because the two electrical switches are mounted on plastic posts with
palnuts, they are not easily removed with good access so you may have to
disassemble the shifter. The main shaft is held in place with a spring roll pin
down at the base of the shifter knob shaft which is mounted perpendicular to
the shaft. Place the shifter assembly on the bench, use a drill to drill a hole for
a punch opposite the bottom of the roll pin through the shifter box. Use a long
punch and hammer to push this roll pin up and out. Pull the main shaft out to
the left via the outer metal arm. You may need a new roll spring pin (p/n
1232645) for reassembly if you destroy the old one. Tips: don't hit the shift
lock solenoid or the plastic or wiring parts while driving the spring pin out.
These shifters do not have microswitches. The neutral safety switch (all
models) is held onto plastic posts with palnuts (p/n 987173). It may be
possible to replace the posts with long metal screws for ease of future
disassembly. If you drilled a hole in the box, plug it with a rubber plug
(hardware store).
1993+: Replacing the Microswitch. The microswitch is on the passenger side,
just beneath the cover, resting on two plastic pins. The park-lock solenoid is
the square box on the passenger side at the bottom, also affixed to pins.
Remove the locking push fasteners and pull out the microswitch and solenoid,
which are wired together. Cut the wires, leaving slack if you ever change your
mind, and tape off any bare wires.
1991+: Replacing the Shift Lock Solenoid. The shift lock solenoid is mounted
on a plastic carrier and is down below on the right, held in place with a small
plastic locking tab. You do not need to disassemble the shifter to replace this.
To release the solenoid, look on the left side of the solenoid near the moving
solenoid post and you will see a triangular locking tab inserted into a Ushaped prong. Using a screwdriver, carefully open the tangs of the prong and
pull the solenoid forward. The bottom is merely held by a non-locking U-tab
on a post. Pull up and out. When reinstalling, use a screwdriver to retract the
solenoid post so that the large U-tang on the triangular plastic locking plate
will engage the solenoid post between the two metal layers.
All: Replacing the Neutral Safety Switch. This is the trapezoidal switch on the
left (below), just under the shift indicator panel. See notes below. You may
need to disassemble the shifter to replace this.
Shift Indicator Bulb. Now is a perfect time to replace this little bulb in the
socket up under the shift indicator.
Re-assemble in reverse order, again being careful about the wiring. The
external arms are parallel with the shifter shaft. Install arms before you
reinstall any spring roll pins. Make sure you route the black overdrive switch
wire down through the shifter with some slack in case you need to pull the
switch in the future. Install back in the transmission tunnel. When you are
underneath the car, clean the overdrive wire connection and preserve with
silicone dielectric paste, then zip tie it in place. Reconnect the shifter rods to
the arms and make sure you drive the circlips home with a screwdriver so
they stay firmly in place. Rotate them to the top of the shifter so they have no
inclination to fall off even if loose.
If you removed the shift-lock solenoid or the microswitch, don't start the car
without putting your foot on the brake. Don't pull an Audi Through the Garage
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Transmission. Automatic AW70 and ZF
Door trick.
Reverse Lights Not Working: Backup Light/Neutral
Safety Switch. [Inquiry] My back-up lights and safety
neutral switch are not working. How do I repair this?
[Response: Rob Bareiss] Your neutral safety switch is the
trapezoidal switch beneath the shift indicator plate on the
2. Remove ashtray.
3. Remove two screws in bottom of black console tray under parking brake
handle (Torx screws on your later model 740)
4. Remove clip at front of tray under ashtray. Adjust shifter and park brake
handle position to allow you to pull tray up, forward, unhook, then back and
twist to get over the shifter handle. The tray is split up front to allow this.
5. -85 740: The neutral safety switch is a black pie-wedge shaped thing on the
left side of the shift lever. Probably 2 more Torx screws hold it in.
6. 85+ 740: Remove the gear indicator cover for access to the neutral safety
7. Later 740/940: Bad news: you will have to pull the shifter to access this
switch which is held in place with pal-nuts and not accessible without
disassembly. See above.
Automatic Shifter is Loose or Moves.
Safety While Working on Transmission. [Editor] Note that you can accidentally
shift your transmission while working around the linkage beneath. To be safe, don't
rely on "park": use jack stands and chocks to hold the car secure.
[Symptoms:] The shifter on my 745GLE (automatic) is really loose. When I put it in
park, I heard a metallic clunking. I can move the shifter about a half inch at the
top forward and back (no side to side movement) when it is in any position.
[More Symptoms on an AW:] Last week I noticed I had to over shift my '89 700's
AW to get the car to go in gear. In general the shift lever was quite sloppy. 2. The
automatic shift lever on my 1992 940 Turbo sedan is very loose when it is in D
drive. It moves forward and back way too much. So loose that it looks like it
moves all the way into N and all the way back to 2.
[Dave Stevens] Apart from climbing under the car to inspect the shifter linkage
bushings, do the following. Put the gear selector in Reverse with the ignition switch
on (and of course with the brakes set). If you move the shifter back and forth in its
detent position and the backup lights go out then the bushings are definitely gone.
Curing Gear Shifter Looseness and Rattles [Tips from Mark] A loose shifter
lever is a common 700\900 series Volvo affliction. Fortunately, the most common
cause of looseness and rattling is easily fixed by replacing three small rubber
bushings (two in later AW-71s) in the shifter linkage (Volvo part number 381704-6
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and associated C-clips (Volvo p/n 951669-1); the rubber part is available in
aftermarket from FCPGroton). Replacing or adding spacers or bushings where
shifter connecting rods attach to the transmission can also fix looseness and noisy
operation relatively easily. Completing the procedures listed below will eliminate or
considerably reduce sloppiness in your shifter. Each of the three sections below
details a corrective procedure for a different section of the shifter linkage. Read all
three before proceeding with repairs to ensure maximum success. Before making
repairs to the shifter linkage assembly discussed in the first two sections, your
Brick must be raised and secured in a safe manner. It is not necessary to raise the
car to make repairs discussed in the last section.
1. Replacing Rubber
Shifter Bushings. The
illustration shows how
the shifter mechanism
is arranged and where
the three donut shaped
bushings are located.
Mark the linkage pin
position with a chisel
so you can replace the
shifter linkage without
having to re-adjust it.
Once the bushings have been located on the car, remove the C-clip that holds
the linkage rod on the pin or arm. This C-clip is often rusted. Take the pin off
the rod, remove old bushing, install the new bushing and replace the C-clip,
making sure you drive it home so it does not fall out. Be sure not to lose the
clips that hold the linkage together and don't take the whole thing down - do
one end at a time and save your self the grief of not being able to remember
which way it went. With normal use, these bushings will need to be replaced
every five to eight years to maintain the new feel of the shifter. The bushings
are a little easier to get in their holes if you let them soak in some very hot
water first, this makes them a little more flexible. Push into the holes with a
screwdriver once you get one side started. Spray them with silicone for better
installation and lubrication afterwards. Tips: the rear linkages require a 15mm
backup wrench; since access is tight, a narrow bicycle wrench helps. The front
pin is often rusted in place. Use plenty of penetrating oil and try to lever it out
with a wide screwdriver. Once you have it slightly out, use Vicegrips on the
wide end to rotate it free.
2. Tightening Shifter Linkage Rod. As the illustration indicates there are two
places where shifter linkage rods attach to the transmission. One attachment
place is the movable gear selector lever. The other connection point is where
the short, double bent shifter rod attached to the longest lever from the shifter
connects to a fixed spot on the transmission body. To correct any looseness
here a bushing must be placed around the clevis pins that secure the linkage
rod to the transmission housing. I fashioned a bushing from a very short
length of clear vinyl hose with a 1\4 ID and 9\16 OD. I do not know what kind
of bushing was installed at the factory since it was completely missing where I
made this repair to my car. The vinyl tubing, however, does an excellent job
eliminating slack and preventing any rattles. Now is a good time to inspect the
overdrive wire as well, since insulation can wear in this exposed location.
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3. Finding the Source of Shifter Rattles In the Console. Remove the console
panel around the shifter and look into the shifter well. A coin or a pen may
have fallen through the shifter gate and is now rattling around.
4. Tighten the Screws Holding the Shifter Box. [Ariel Rocchio] The shift lever
is secured within a box. At each of the four corners of the box there is a
10mm bolt with a washer. If these loosen, it can cause play in the shift lever.
Tighten these bolts using Loctite Blue. There may be rust in the holes since
they open to the driveshaft tunnel below. The front two bolts may be obscured
by wiring or a bolster support.
5. Adjusting the Shifter Linkage Adjustment [Dave Stevens] It's very easy to
check shifter linkage adjustment. With the gear selector in Drive, note the
freeplay from the detent position to the stop when moving the shifter forward.
Then in 2nd, note the freeplay from the detent position to the stop when
moving the shifter rearward. The freeplay travel at both ends should be equal.
If not and provided the nylon bushings are intact, adjust the trans shifter
linkage accordingly.
Your shifter can also move due to transmission mount failure. A small amount of
movement in response to drive train movements is normal.
Removing Shifter Knob and Overdrive Switch.
740 Cars.[Tip from RHaire] To remove the shift knob, carefully pry any chrome
trim off. Note it has a seam that will allow you to open it up. Place a baggie over
the knob to contain flying parts. Take a crescent wrench and open it just enough to
slip around the shifter shaft and place it up against the knob. Tap up on the
wrench with a hammer and you will knock the knob up and off.
[Response: Editor] To remove the overdrive switch, pry it out from the head of the
shifter. This has two small wire connectors entering it. Check that the wires are not
abraded and the connectors are intact and firmly mounted inside the switch. If you
need to replace the switch, realize that the wiring goes down the column, out the
bottom of the shifter assembly, then far up into a connector behind the relay
panel, and is a pain to replace. Try to repair the switch if you can; if not, wire in a
new switch at the shifter.
940 Cars. [Tips from Jay Simkin] Tools needed: soldering iron (25-40 watt),
needle-nose pliers [bent tip], pocket knife or utility knife.
1. Remove overdrive switch from knob housing. Using tip of utility/pocket knife,
pry the over-drive switch from the knob. Little effort is required to do this.
2. Get slack in wires to overdrive switch. Using bent-tip needle nose pliers, grip
the insulation sheathing around the wires that go to the switch. Pull GENTLY.
There is perhaps 1/4" of slack to be had - and you will need it - but you must
pull gently on these wires. They are thin. (If you break them, the shifter will
have to be removed and disassembled to replace this harness. This is a nontrivial task.)
3. De-soldering wires to overdrive switch. Once you have the switch body outside
of the shifter knob housing, use white-out to mark one side of the switch box
and the wire that runs to that side of the switch. Use the soldering iron to
separate the wires from the switch body. If the wires have been spot welded,
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Transmission. Automatic AW70 and ZF
cut the wire as close to the switch tab as possible but do not cut off the tabs
themselves. Set the switch aside.
Removing the shifter knob. The gear shift knob is held to a hollow steel shaft square in cross section - by small tabs on the inside of the polymer knob.
These tabs are not destroyed when the knob is removed. Rather, they are
pulled out of recesses in the metal shaft. The tabs reseat when the knob is
reinstalled. Move the shift lever to the 2nd gear position. Grip the shifter knob
with both hands and pull upwards using a robust tug. It will release suddenly.
Protruding from the gear selector housing, you will see a square steel shaft,
with a plastic shift unlock rod inside of it. Nothing need be done with these:
There is no link between the plastic rod and the button. The top of the plastic
rod bears on the underside of the button, mounted in the top of the shifter
Attaching guide wire. To ensure proper routing of overdrive switch wires inside
the shifter knob housing, solder the end of a piece of thin, flexible wire to the
end of one of the overdrive wires. Thread the guide wire up through the
channel in the shifter knob housing, and out through the opening for the
overdrive switch.
Installing the shifter knob. Making sure that the opening in the shifter knob
faces towards the back of the car (and the shifter button faces the console),
put the shifter knob onto the square shaft. It will slide freely, until it comes to
about 1/4" from the bottom. As the shifter knob slides downwards, pull gently
on the guide wire, to pull the overdrive wiring harness up towards the
overdrive switch housing opening. Once you can see the end of the wires
through the opening in the knob, use the bent-tip needle nose pliers to pull
the wires out through the opening.
Seating the shifter knob. Using the flat of your hand, press down firmly on the
shifter knob. This will seat it. It will self-lock into place: you will feel the clunk
as it self-locks. The plastic rod inside the square metal shaft will self-position
against the underside of the shifter knob button. Check that this is so by
moving the gear selector through its positions. It should do so.
Re-installing the overdrive switch. Using your soldering iron, attach the
overdrive switch wires to the switch tabs. Put the key in the ignition and move
the key to position two. Press the over-drive switch button several times. If
the arrow-head indicator on the right side of the warning light row at the
bottom of the cluster goes from on to off as you move the switch button, you
have a good contact. If not, re-solder and repeat the test.
Closing-up. Push the overdrive wires into the recess, gently. Press the
overdrive switch back into its recess.
Re-test. With the ignition key in Position II, function test the over-drive switch
again. If it does not cause the arrow-head indicator to go on and off each
time, remove switch from shifter knob housing and check the solder joints.
Not knowing that the shifter knob is not linked to the shifter's internal mechanism,
I dismantled the shifter, which I bought at a salvage yard. If you want to remove
the knob at a salvage yard, you need only cut the over-drive switch wires, and pull
the knob free. Only the overdrive switch wires keep the shifter knob from being
removed without tools. [Doug Peterson] Doug could not remove the shifter
knob/rod at all, ended up breaking the knob assembly off. He also broke off the
plastic shift lever rods within, repairing them using superglue and metal pins drilled
into each broken end.
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Replacing the Overdrive Switch Using Volvo OEM Parts. [Editor] If you have a
break in the wire leading to the overdrive switch, buy the Volvo OEM replacement
part number 9130297. This comes with a long pigtail from the switch leading to the
connector. To replace it, you will have to remove the entire shifter assembly to
feed the wire through. This also requires removing the passenger glove box and
right side console cover to access the connector, which is about five inches forward
of the relay tray and under the carpet on the right. After pulling the shifter head,
tape your new wire to the old one and pull it through from the connector. Make
sure you pull the wire snug at the bottom of the shifter assembly leaving no slack
inside the shifter shaft, since the unlock rod inside the shifter shaft tends to push
against the overdrive wire: it will wear and also push the overdrive switch out of its
recessed hole. Reinstall the shifter assembly.
To Remove Coins or Objects in the Shifter Well: [Jay Simkin]
1. Use a three-prong gripper (you press the button at the top, and the prongs
emerged from a coiled-wire sleeve; release the button and the progs retract,
closing around an object).
2. Put a lump of butyl rubber (known as "body caulk", a black, sticky rubber
sealant used on auto glass, etc., and available at auto glass stores or NAPA) at
the end of a dowel rod, and go fishing for the coins. If the butyl rubber is
pressed against the coin, the coin will not fall off, and you should be able to
extract it.
3. Use a Shop Vac crevice tool to suction the coins from wherever they've
Replacing 940 Shifter Knob with 960 Wood Version. [Jay Simkin] You can
upgrade your 940 plastic shifter knob to the classier 960 wood version quite easily.
The plastic handle is Volvo p/n 6843471 ( $60-65 at the dealer.) The red walnut
handle is p/n 9166797 ($220 at the dealer) will interchange with the plastic
version. You can find both on EBay for $20-$30.
Shift Indicator Lamp Replacement. See the Electrical: Instruments section for
Shifter Detent Button Pops Up. [Inquiry] The button on my shift automatic shift
lever popped up yesterday. This won't allow the lever to be moved into park. I
pulled out the button and shaft and it looks like it is attached at the bottom with a
circlip. What's the fix for this?
[JohnB] The shift detent rod is attached/held into the detent mechanism with a
hardened steel roll pin. The roll pin is available from the dealer. To reattach it to
the detent mechanism separate the rod from the big square may be
able to save the button but chances are you'll need a new one. You'll have to
remove the center console cover to get at the shift mechanism and you may have
to remove the neutal safety switch to get at the detent mechanism. Anyway,
remove the old roll pin from the detent mechanism and put the detent rod in past
the two holes in the detent mechanism. Start the roll pin in one side and use a
pliers or pry bar to get the roll pin in past the notch (what you think is a circlip
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Transmission. Automatic AW70 and ZF
setting is a groove all the way around the rod) and into the hole on the other side.
Put everything back in you had to remove to get to the roll pin and take your old
saved big square button or a new one and snap it onto the detent rod. Be aware
the big square button goes on either way, but one way the button has a
symmetrical relief to the shift selector knob...wrong way and it sits up at an angle!
If this doesn't work you'll have to remove the entire shifter assembly...disconnect
the AT linkage under the car, disconnect the OD wire from the solenoid...there
should be a connector between the solenoid and the wire (it was yellow on my
car), disconnect the torque stay from the shift assembly, disconect the electrical
bits from the shifter inside the car, remove the four bolts holding the shift selector
mechanism and lift the gear selector assembly out. You should now be able to get
to the roll pin easily. Since you have everything out, now is the time to replace any
plastic bushings that are worn or missing and I would probably replace the OD wire
too. The part that goes under the car (through a grommet in the shifter assembly)
gets oiled and contaminated and the insulation turns to putty and eventually flakes
off. The 87 OD wire on our 760 went about 2 years ago.
Auto Tranny Refuses to Reverse: Mount Replacement. [Inquiry:] My 87 764
Turbo has 124K miles and the AW 71 transmission has been serviced every 25-30K
miles. Recently it has started to refuse to go into R gear after 10-15 miles of
operation in D. The selector seems to operate normally with all the usual detents,
but the transmission is still in pseudo-D when the selector is in R as the car will
creep forward. Putting the selector into P results in a slight lurch forward and then
the transmission is properly locked in P.
[Response 1: Rick] Sounds like the linkage is misaligned. That is, your gear lever
isn't aligned to the gears positions on the transmission.
[Response 2: Michael Jue ] It could be something more (read: internal) but I'd
concur with Rick on this being the first course of inspection. Something else you
should seriously consider...especially if the shifter is maladjusted as above: the rear
transmission mount. I'd been having a number of small niggly shifter issues in
which the shifter felt right but the indicator never showed in the clear windows at
the base of the shifter. Then, finally the neutral safety switch failed to work.
Diagnosis: bad transmission mount. Sheared the rubber mount from the metal
surrounds. Easy fix (see below). All symptoms disappeared.
Changing the Transmission Mount:
[Tips from Michael Jue and Dan] Jack up the car and support the transmission with
a jack. Use a rag or block of wood to prevent scratching the transmission case
(don't support it under the pan!). Remove the nut in the center of the
mount/crossmember that holds the mount to the transmission. Remove four bolts
securing the cross member, then lower the cross member. Unbolt the mount from it
and install a new one. The job takes about 30 min.
Transmission Output Shaft Bushing.
Why Replace the Seal and Bushing?
...we replaced ours ('89 745) a few months ago, at approx. 115,000 miles. Why? I
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noticed that the output shaft was spraying a bit of oil onto the underside of the
car... and my experience teaches me that such leaks only get worse, plus tailshaft
play accelerates other wear. [Tip from Randie Starkie] My experience is that the
bushing needs replacement about every 150,000 miles. I personally have never
replaced a seal without the bushing being bad. The seals seem to hold up as long
as the bushings aren't worn.
Let me say that this is not necessarily bad or that you don't have an output
bushing worn and a seal leak. First, when the bushing's worn, you usually get some
driveshaft vibration, or humming/drumming in the car. So when the new bushing's
in, it's noticeably quieter. (That was my experience on my '83 and '86 GL's, both
receiving the bushing & seal at around 200k.) Second, if the machined outer
surface of the companion flange is worn where the seal rubs, there's a possibility of
driving the seal 1/8" further into the housing so the new seal sees a fresh, nonworn surface. It all depends on how the original was mounted. You should try
shaking the driveshaft radially at the transmission and see if there is any lateral
movement...if you're unsure try shaking a known good one. Also, you can replace
the seal yourself and leave the bushing will seal for awhile, perhaps a
LONG while. Last point ...when replacing seals like these, check the metal part that
the seal rubs against...if there is a notch you can catch your fingernail on you
probably need to replace the metal part too...a rear axle pinion flange is easy but a
driveshaft yoke you have to replace a U-joint, etc. (some people think U-joints are
This is part of what I'd refer to as preventative maintenance. I was quoted a price
of $300-$350 to replace the seal/bushing. Bought the parts for about $45 (parts
replaced were output shaft bushing, output shaft seal, rear housing gasket) and
performed this operation myself in about 3 hrs, including setup/replace/cleanup
time. Pulling the housing is relatively straightforward once the tranny's supported
and the cross member and mount are removed. I believe that there are six bolts to
remove and the housing's in your hand. Have a new gasket on hand and make sure
that both mating surfaces are completely clean with no trace of the old gasket. You
don't want to have to do this job a second time because of leaks.
[Another tale:] The tail housing removal is really pretty simple. I just finished
replacing a transmission in my '89 744 project car. The tail housing was cracked
and we initially hoped to replace only the housing, but Volvo wanted $253 for it
and the junkyard had an entire AW70 for $400. Anyway the Dexron is still in my
hair from finishing up the job, so my experience is as fresh as it gets. [Another Tip]
Now is a perfect time, while you have the drive shaft disconnected and good access
from below, to replace the tranny mount and the tranny linkage bushings.
Identification: Bushing versus Bearing:
[Note from Abe Crombie] The 93 through '95 model AW71
gearbox has a ball bearing instead of the earlier bushing. You
can tell by looking at the output flange where driveshaft
attaches. The bushing style has no bell shaped
slinger/protector for the seal; the bearing type has this type
flange. The slinger/protector prevents you from seeing the
seal. The standard flange on the bushing versions allows you
to see seal on tailhousing. The bearing can't be used in place
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of the bushing as it requires a different output shaft in rear of
trans; and it is costly. This style has an oil seal at the rear of the housing and an
o-ring inside. Repair is simple: just pull the housing off and replace both the seal
and the o-ring.
Procedural Notes:
What you're going to do is take out the bolts that connect the output flange to the
driveshaft, support the tranny and remove the rear transmission mounting bracket.
Four bolts hold the tail housing to the rest of the transmission case.
Tool Rental:
[Editor] There is a tool available that pulls the old bushing out. It is no longer
available from IPD due to "quality control problems."
[Cautionary Tale regarding the IPD tool:] I attempted to replace the tailshaft
bushing/seal with IPD parts and their rental bushing removal tool that allows this
to be done quickly and easily without removing the tailshaft housing. The removal
tool didn't function quite the way I had imagined. The puller's center bolt got
tighter and tighter until it sheared off about two inches from the bolt head. But
wait, it gets worse... I removed the tailshaft housing and discovered the removal
tool shaft is wedged into the tailshaft end bolt hole and I can't get it out. There
were wire lacing threads around the hole so I don't know if my tranny is toast or
not. The tailshaft housing was removed without damage. The broken bolt is
currently stuck in the tailshaft end bolt hole (no better way to describe it).
[Another Tale:] The exact same problem happened to me on my 240 this past
weekend with the same tool. Amusingly enough, I was able to get the broken bolt
out by using a pipe wrench, and a LOT of elbow grease. Although there was some
slight thread damage in the hole in the output shaft, it wasn't severe, the bolt
ultimately torqued up with no problems, and I haven't had any more trouble with
it. This is what was recommended by my mechanic, when I called him. After the
bolt from the tool has been successfully extracted, spray WD40 into the bolt hole,
holding a white cloth underneath to catch what comes out. This is to flush out any
loose threads that would cause MORE trouble. Then experiment with threading the
driveshaft collar's bolt into the hole, to determine the extent of the thread damage.
If it appears as though the bolt will be ruined and won't torque to spec, the hole
will need to be re-tapped. IPD, incidentally, was gracious about the problem, and
agreed to refund my money. Since I didn't have any major transmission damage, I
didn't ask for anything else.
[Procedure Notes 1:]
Start with the driveshaft bolts while the car is still on the ground. That way you can
roll the car a little to get to all 4 bolts *easily*. If you're driving up on ramps like I
did, this won't work and you'll need a crow's-foot wrench (my 9/16" worked fine)
to get to the ones on the top of the flange. A generous supply of profanity helped
in my case... It's a good idea to mark the output flange and shaft flange so you
can mate them up when the time comes to put it back together [critical for proper
driveshaft balance.] Once the bolts are out, push the driveshaft toward the rear of
the car and it will pop out of the flange. You can shove it up above the flange to
get it out of the way. Raise the car up (jackstands, ramps whatever)if it's not
already and drain the tranny fluid. Put the selector in Park and use a 30mm socket
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to remove the bolt in the center of the flange. This bolt holds the flange to the
output shaft. Once it's out you can pull the flange out of the housing. Remove the
15mm nut in the middle of the transmission mount (rear end of transmission).
Support the pan with a piece of wood held up by a floor jack, just enough to take
the pressure off the tranny mount. You should see the mount bolt come up slightly.
Then remove the four bolts that hold the mount to the chassis.
The mount will come off, and the tail housing will be clearly visible. Four bolts
(14mm I think) hold the housing to the main body of the tranny. The top and
bottom bolts are different lengths, so note where they came from. With a little
gentle persuasion, the housing will come off. On my particular car, the PO slid it
into a ditch and caught the end of the center mount bolt which cracked the
housing. This also saved me the trouble of taking off the L mounting bracket. It
won't have to come off if you just plan to replace the seal. The seal is easy to get
to and *looks* like you could pry it out with a screwdriver, but I have never tried
this. You're going to end up with a roughly 6x6x8 inch housing which you can work
on at your leisure. If you don`t have the tools to remove/replace the bushing, you
can just bring the housing to almost any auto service shop and they will be able to
press a new one in for a few bucks. Plan for about 2 hours under the car to get it
out. If the gods of rusted bolts are on your side, it could be done in 45 minutes or
so, I'd guess. Nothing is particularly difficult about the operation. Although I
recently told someone to shoot me if I ever said it, installation is the reverse of
removal (BOOM). See orientation notes below. The center flange bolt only holds the
flange to the shaft; no pre-tensioning or any of that other technical stuff.
[Procedural Notes from Bill Lauber:] Volvo AW70 Rear Bushing
Regarding Volvo Automatic transmission AW70 rear bushing replacement ...I found
significant play in the end shaft and proceeded to get the parts from my local Volvo
dealer. The bushing was quoted at $36 with the seal at $11 and the gasket for
about $5. I checked the yellow pages for a automatic transmission parts house ..
found one and learned the following. They carried every thing I needed, the only
difference being I carried the parts out for a total including tax of $9.70. A entire
rebuild kit for the Volvo automatic was quoted at $108.00 and the dealer said the
Volvo AW70 was one rebuild an individual could be successful with. I have installed
the bushing, seal and gasket and all is working well.
I used drive on ramps at the rear wheels not the front. This keeps excessive loss of
ATF fluid when removing the rear housing. HINT, with front wheels blocked from
rolling, elevate one side of the rear all to allow rear wheel to spin on one side. This
allow all to spin for easy access to drive shaft bolts as long as the transmission is
in neutral and the emergency brake is off.
1. Place support under transmission pan that can be raised and lowered as
needed A board between the support and pan will help distribute the weight
normally handled by the rear transmission support which has to be removed.
2. Remove rear transmission support bolts from car frame and end of
transmission and remove cross member
3. Disconnect speedometer hold down bolt at transmission then unscrew cable
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Transmission. Automatic AW70 and ZF
from transmission
4. With transmission in neutral, disconnect end of drive shaft from transmission
5. Insure transmission is in park
6. Remove transmission shifter link's rear pin ONLY allowing link to move out of
the way
7. Remove 30mm bolt from rear of shaft on transmission. Remember step 5 ...
pull out shaft end
8. Remove all 6 bolts holding rear housing
9. Remove housing HERE COMES THE ATF! (you will lose about a quart)... you
may have to tap with block of wood to break loose from gasket. be gentle so
not to crack the housing
10. HARDEST STEP for me ... remove the old gasket material [Editor's Note: See
Removing the Gasket]
11. Punch out the old seal and bushing ... the seal was easy ... the bushing
requires care not to crack the housing. You may want to have a machine shop
remove and replace the bushing. I was successful but could just as well
messed up at this point
12. Install seal & bushing in housing [Editor's Note: See Bushing Orientation]
13. Install housing with new gasket and six bolts
14. Insert shaft with some ATF on bearing, seal and shaft. [Tim] After the flange is
installed it will fit tightly in the new bushing.
15. Torque shaft bolt.
16. Hook up shift linkage
17. Shift to transmission to neutral
18. Install drive shaft and bolts spinning elevated rear wheel for easy bolt
19. Install speedometer cable
20. Install cross member ... elevate transmission as required
21. After removing car from ramps check ATF and add as needed.
[Another Procedural Note from Don Foster:]
The parts you'll need are: new bushing; new seal; new gasket. In general, the
procedure is:
1. Jack up the car -- from the rear may be preferable.
2. [Editor's note: mark the flange and shaft for proper balanced reassembly.Carefully mark the linkage placement before removing it from the
side of the tailshaft housing.] Drop the driveshaft at the tranny -- I don't think
it needs to be removed any further, only pulled aside.
3. Remove the companion flange -- I used an air gun (with the tranny in park).
Some purists among us will probably tell me how wrong that is -- but both
cars logged at least 50k flawless miles since.
4. Drop the crossmember -- you might want to support the tranny.
5. Remove the speedo cable.
6. Position a pan under the rear of the tranny -- some fluid might decide to get
in your face. Transmission fluid will run out when you remove the piece the
driveshaft was bolted to (flange?) as well as when you loosen the tailshaft
housing so be prepared with a pan to catch it.
7. I think you need to remove the tranny mount bracket from the housing to
gain access to the housing bolts.
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8. Unbolt the housing from the tranny. Pull back gently -- a little tapping may be
9. Knock the old seal out of the housing. The oil seal is the metal
ring/lipassembly with rubber molded around it. Both the rubber and the metal
ring/lip come out.
10. Note the orientation of the old bushing as a reference for installing the new
bushing. Note as well the orientation of the hole to the groove. in the housing.
Examine the inside of the housing -- note there is a 1/4" gap, or opening,
under the bushing, at the bottom of the housing
into which you can cut.
11. Using a hacksaw blade, cut through the old
bushing into this opening. Note the orientation
of the original and align the new bushing the
same way.
12. Peel the old bushing inward and it'll pull right
13. Scrape off any gasket material (most frustrating
part of the job.) [Editor's Note: See Removing
the Gasket]
14. Wash the housing, insuring that all chips are
removed. [See Chip Removal]
15. Be sure to prelube the new bushing and new
seal before final assembly. Position and orient the new bushing -- and using
either a proper bushing/seal driver OR a socket of the correct diameter
(perhaps with a 6" extension on it), drive the new bushing into position. I've
found it slides into position easily, with only slight tapping from a hammer.
[See Bushing Orientation] [Tip from Randy:] My automotive supply store has a
full service machine shop and I never mess with this stuff- I take the tailshaft
to them and have them press in the bushing. For the seal I apply a coating of
grease to the outside diameter and tap it into place with a socket just slightly
smaller than the diameter of the seal.
16. Examine the new bushing to confirm the edge was not dented -- if so, clean it
up slightly with a fine rat-tail file (and rewash). Be careful to not damage the
main bearing surface of the bushing.
17. Drive the new seal into position. I like to use a touch of Permatex aircraft
gasket sealer, but it's not necessary.
18. Clean any remaining gasket from the mating transmission surface.
19. Install the new gasket. Again, I like to use a touch of gasket sealer, but it's
not required.
20. Lubricate the bushing and seal with ATF.
21. Position, install, and tighten the housing.
22. Wash the rear flange, lubricate the bearing and seal surface, and slide it over
the splined tailshaft. [Tim] After the flange is installed it will fit tightly in the
new bushing.
23. Install and tighten the nut. I'm sure there is a proper procedure and torque.
24. Install the speedo cable.
25. Lift the tranny and install the mount bracket and crossmember. This might be
a good time to install a new mount.
26. Connect the driveshaft. [Editor's Note: 30 ft-lbs.]
[Tip from Randy:] On assembly be sure to bolt the linkages according to the marks
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you made before disassembly. Don't forget to check the transmission fluid level,
particularly if you lost some during this work.
[Removing the Gasket: Randy] I've replaced two bushings and both times the
most time consuming part of the job is removing the gasket between the
transmission case and the rear housing from the transmission case. There isn't a lot
of room to work your way around with the various tools to scrape the gasket off. I
found a single edge razor blade worked best for me, and the second time I did it I
was armed with a spray on gasket remover which helped a whole lot. Spray it on,
let it soak, scrape a little.... repeat numerous times, being careful not to dig into
the soft aluminum case when you become frustrated and begin to use that sharp
wood chisel that always worked so well on removing gaskets from cast iron
casings. Also it would probably be in your best interest to take extra pains to
protect the exposed portion of the transmission from consuming the gasket pieces
and various bits of underbody debris you will rub off with your arm- I wrapped
mine in a clean rag (the rear of the transmission, not my arm)
[Chip Removal: Paul Seminara] Replace the bushing, when you do the rear seal.
Indeed the bushing will wear and sometimes the wear will be from small bits that
wear the tailshaft flange as well. This is especially so on high milers. This usually
will require replacement as well.
AW-71 Auto Trans Output Bushing Orientation Question. [Inquiry:] In
replacing the auto trans output bushing, which way does the hole in the bushing
[Response: Patrick Petrella/Scott Cook] Some bushings come with a hole, some
come with no hole in the side. Some confusion. After consulting an expert, I found
there is no particular way to align the bushing UNLESS THE BUSHING HAS A HOLE
IN IT. If there is a hole in the bushing, then the hole should be positioned over the
groove for the oil, or the bushing and tailshaft will get no oil. See the photo above.
Hint: make sure you get the correct part for your application.
Seal Leakage in AW70L Transmission. [Inquiry:] Oil is leaking from my AW70L
transmission at the shift linkage shaft on the right side of the tranny housing. Does
anybody know how it is to replace the seal(s)l ?
[Response:] That shaft goes through the tranny from one side to the other, with a
seal on each side. On my '83, the seal had simply popped out of the transmission
housing, and only had to be gentle pushed back in. The bad news is that -- at least
in my experience -- access to the seal is restricted by the exhaust pipe. Dropping
the pipe first made it much easier. One thing I'd advise is to first clean up that
area of the transmission, particularly if it's been leaking for awhile. A lot of dirt and
grime will accumulate -- and you want the area as clean as possible before
installing a new seal. I washed it down with parts cleaner, hit it with compressed
air, and let it dry.
AW-70/71 Hard Shifts.
Symptoms. The AW71 in my '86 740 used to shift very hard from 1st to 2nd gear.
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This shift is the first shift and it usually happens at about 20 km/h (depends on
how hard you accelerate). It felt almost like getting rear-ended. [Editor] Hard 2-3
shifts are also symptomatic.
Try the Easy Things First. [David Hunter] A flush may cure the shift problem. On
my 88 740 at around 240K I encountered delayed shifting from 1st to 2nd and 2nd
to 3rd. Also had OD problems. After checking the common causes such as
kickdown cable, OD relay and solonoid I elected to do a flush with Mobil 1
synthetic. The results were immediate and dramatic: all problems went away. In
addition, check the kick down cable adjustment regarding those hard shifts. You
may be pleasantly surprised.
Worn Valve Ball. [Toni Arte] The real cause for this problem is a worn valve ball
in the transmission valve body. This ball is the 15C in the picture. This is a picture
of the lower valve body. A replacement valve ball is available, you can order it from
your local Volvo dealer. The part number is 1377746-1 (small blue valve ball). [Tip
from Herman] You may need gasket kit p/n 271292. Before you do the job, buy
the OEM manual: the manual number is TP 31642/1. The manual is for
AW70/70L,AW71/71L, and AW72L. The L means lockup, check the tag on the
tranny before you buy your gasket kit. For detailed instructions, see Brad
Wightman's excellent illustrated writeup.
In my case the 5.5 mm valve ball was worn to about 2 mm size. Note that the
valve body can be accessed through the oil pan, so it's not necessary to drop the
transmission. A competent transmission shop should be able to change this ball. In
my case the cost was about $100, this includes two hours of labour, new gaskets
and fluid.
[More from Herman] Great care needs to be taken upon disassembly however it's
an easy job with some potential of going very wrong. I tried the wrong way first. I
disassembled enthusiastically and lost one ball of about 15, dropped a retaining pin
and then wasted 2 hours scratching my head and agonising about the lost ball. A
friend had a dead AW71 and let me take it apart for reference. This time I followed
the manual and compared the two valve bodies. The job was dead simple once I
went about it the right way. GET THE MANUAL and follow the steps that get you to
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opening the valve body up. The manual says nothing about the balls so you need
to locate them and note ON PAPER where they go. There are a lot of balls and
things that can go flying and falling into your parts cleaner. Following the steps in
the manual however, takes away that risk. As in the photo on that page, my ball
was worn to half the size of the new one and was blown out from its seat and had
gone somewhere else. I think I replaced about 5 maybe 6 quarts of fluid (I use
only AMSOIL). Make sure you have a lot of good quality paper towel (cloth fibre
won't break down should it get into the gubbins) for the job and a large clean welllit bench surface.
[Tip from Gary De Francesco] Rough 1 - 2 shifts are a possible sign of a worn
rubber ball in the valve body that regulates how fast the various clutches and
brakes are applied. As the ball wears, the fluid flow rates in some of these
regulating passages can increase which will cause the various hydraulic actuators
to engage faster. This will feel like a sudden and rough engagement. On the one
hand, with fast engagement, there is little chance for the clutches and brakes to
slip. This means less wear, and hence a longer lasting tranny. On the other hand,
these fast engagements result in a bit of jarring to the occupants of the car. The
solution is to have the valve body serviced. This can usually be done without
removing the tranny. So you have to decide. Can you live with a little jarring, or do
you want to spend some money and see if it can be smoothed out.
Overdrive Relay and Function:
Overdrive Operation. [Roger Scott] The overdrive electrical circuit works works
like this -- the A-70/1 automatic transmission is a 4-speed transmission, but,
unless the overdrive solenoid is energized, it is by default a 3-speed automatic
transmission. When you hit the overdrive button what really happens is you deenergize the solenoid, disabling 4th gear; you get a downshift to 3rd gear and the
up-arrow light on the instrument panel.
Basic Diagnostics. [Roger Scott]
Check fuse 12: intact, ends are clean and it fits tightly.
Check for fraying or severing of the wires to the solenoid - under the car on
the left side of the transmission. Pay particular attention to the metal retaining
clamp near the front end of the shift lever where the wires pass through.
Make sure the wires to the switch on the shifter head are in good order. You
can remove the relay and test for continuity between terminals 1 (15 on the
relay) and 4 (86 on the relay) which are the switch wire terminals.
You can test the relay and solenoid by jumpering with a spade-terminal
jumper wire. Pull the relay, jumper between terminals 1 (15 on the relay, or
+12V) and 3 (87 on the relay, or the solenoid). This bypasses the relay and
energizes the solenoid directly. Or run +12V directly to the solenoid through a
long jumper wire from the battery.
[Don Foster] All this having been noted, 90%+ of overdrive failures result
from relay solder cracks. See below for instructions for relay repair.
Relay Problems and Repair:
[See Relay Locations for a detailed picture of relay location and removal
instructions.] [Symptom:] I have a friend with a '90 740 automatic
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Transmission. Automatic AW70 and ZF
and he is having intermittent OD problems that seem to be weather
related. It won't go into OD when the weather is cold. Is the relay
on the relay tray? If so, which one is it?
[Diagnosis:] Yes it does sound like an OD relay. If I remember correctly on 740 it is
by the Ashtray/FuseBox. It is pretty common component failure on the bricks. It
will be a white Hella relay. Pretty simple to change. The relay is about $40-43
through Mail order from dealership. In my case I was sure it was the wiring, switch
or solenoid, as the relay looked just fine. But as soon as I replaced the relay, all
problems disappeared. The relay is about $40 from the dealer, or you can probably
find it cheaper from a second appears to be a standard Hella relay.
[Response 2: Michael Daley] I have just repaired the o/drive relay and rather than
pay the UK£40 that the volvo dealer wanted for a new one, I took the top off the
relay - all that was wrong with it was a cracked solder on the circuit board. Fixed
with a soldering iron in 5 minutes, saving myself £40!!
[David Brewster] Wave solder joints can crack
and cause relay failure, as shown in the photo.
These can be easily repaired with a soldering
iron. For a more detailed discussion of relay
repair, see Relay Repair vs. Replacement.
[Another OD Symptom:] I have a '93 940T with
an AW71L transmission (or so I've been told...)
Today I was driving on the highway and it
momentarily dropped out of overdrive into 3rd, at
the time I was at minimal throttle. I dismissed
that as a hiccup. An hour later (after making a
couple of stops)I began driving and I noticed that the tranny would not go into OD,
3rd gear was the max. All of the other shifts are perfect. I tried pressing the OD
cancel button a few times, and I checked the related fuses - no changes. Am I
looking at replacing the overdrive solenoid on the tranny? If so, can anyone give
me a part# and/or approx. price? [Response: Abe Crombie] It is an AW71 no L.
The turbos didn't get the locking torque converter feature. The trouble sounds like
the typical OD relay failure. The relay is behind the ashtray in the fuse/relay panel.
I believe it is white on that car and square in profile. The fuel system relay is the
one to the left that is rectangular.
Shifter Overdrive Switch:
[Inquiry] My overdrive will not lock out and the relay is fine. [Response: Editor]
The switch on the shifter is likely bad. To replace it, see the link above.
If your overdrive engages late or not before the transmission warms up, first try
replacing the relay and flushing the fluid. If this does not solve the problem, a new
solenoid often will.
AW 70/71 Overdrive Problems: Wiring to Solenoid, Solenoid.
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Electrical & Wiring Problems:
[Rob Bareiss] The overdrive solenoid should click on and off with a very noticeable
click. You need to be sure you're getting 12 volts at the solenoid. If you haven't got
12 V, you need to check the wires at the OD relay socket in the fuse box and
thence to the solenoid itself. My '88 has had numerous problems with the electrical
connections at the OD relay on the fuseblock, so I would be checking there first.
Wiring Connector: [Eric C] The plastic wiring connector which connects to the
overdrive solenoid (attached underneath the car at the rear of the transmission)
can come loose. In my case, it snapped in place yet had 2mm of play and was not
snug. I cleaned out the connector with contact cleaner, allowed it to dry, then used
heat shrink tubing to keep the connector in the snug position after snapping in
closed. It worked; no more overdrive problems.
[Another Tip] Sometimes there is corrosion in the joint between the connector and
the may look fine and even will light a test lamp but will not allow enough
amps across it to fire the solenoid. Take it apart, clean and deoxidize, then
reassemble with silicone grease.
Wiring. [C. McGrew/Scott] Check the wiring under the car from the shifter to the
solenoid. It tends to deteriorate near the shifter and at the connector leading to the
solenoid itself. Jiggle this to find internal wiring breaks. If you install a new
solenoid, then also install more chafe guards (3 inch pieces of hose) all along the
wire. Make sure that the white wire that comes down from the shifter does not
ground out on the car due to worn insulation. [James Souther] A couple of my
solenoids had the white wire break from vibration right before the soldered tab
under the rubber potting, a bit of solder and RTV for potting and the solenoids were
returned to service costing only the two new o-rings.
Solenoid Operation/Diagnosis:
[Rob Bareiss/Scott] The solenoid is normally closed, cutting off the fluid flow
necessary for 4th gear or "overdrive". When energized with the overdrive arrow
light "off" the solenoid opens up and allows the trans to shift into 4th. The solenoid
must pass fluid through when energized, or it's either not working or plugged up
with dirt. Just because it "clicks" does not mean it is passing any fluid. The first
test is to park in a quiet place, open the drivers door and switch the OD on and off
while listening for a click under the car. If you don't hear it then it is bad. If you do
hear a click that does not necessarily mean it is good: it could be dirty and not
passing fluid.
[Steve Sakiyama] There have been a few posts on autotrans overdrive problems
(won't shift into 4th) when the brick is cold. The problem disappears
when the car warms up. I have an AW71. When cold it would not go
into 4th (OD) until the car had been driven for 10 minutes. This
would happen more and more frequently until it was a regular
pattern. I checked/dealt with fluids, OD relay, wiring, and downshift
cable but the ultimate problem was the overdrive solenoid which sits on the side of
the tranny. Although I had bench tested it and it seemed fine,an experienced
tranny tech said it just doesn't sound and feel right. Replaced it with a used one
(with the two inner o-rings), and the brick is fine. [DougC] According to Bentley,
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with the solenoid in your hand and disconnected, you should cover the oil passages
between the o-rings, and blow through the hole on the end of the solenoid. The
valve should be tight, and no air should pass through. With it energized with 12
volts, you not be able to blow air through with the same holes uncovered. It says
also to check for blocked passages and damaged o-rings.
Solenoid Removal/Replacement:
Tools. What kind of special wrench do
I need to get 2 bolts out of solenoid to
remove it? Doesn't appear to be much
room for tools or hands.
[Ryan Ridgely/R Haire/SML] Wear eye
protection. For ease of removal,
GearWrench brand ratcheting box
wrenches with the flexible head work
well and do not force you to drop the
transmission. Support the transmission
with a jack and remove the cross
member (although one user did the job
whilst lying on the right side of the car and reaching underneath). Then lower the
trans about an inch to give you enough room to CLEAN the area around the
solenoid until it is spotless before ever attempting to remove it. Do NOT lower it so
much you crush the distributor cap against the firewall. To remove the solenoid,
you need a stubby angled 12 mm wrench. The rear bolt is the more difficult of the
two. It is snug up in there and you do not have much range of motion. A "gear
wrench" is ideal to turn the bolt. Be prepared for a lot of oil to run out: about a
quart/liter. [Tip] I have used a short (approx. 6") angled/bent 12mm open end
wrench that I heated and bent myself. Access is difficult: you may have to remove
the linkage and drop the transmission support (placing a jack and large wood plate
beneath the pan to support the tranny). [Tip] Bend a flex socket handle to fit and
use a 12mm socket on the end to remove the solenoid bolts. [Tip] Use a smaller
1/4 inch drive socket set to remove it. Note that there are two o-rings to pull out.
Dirt. [Rob Bareiss] Replacing the solenoid requires that NO dirt get in that
transmission. Lots of brake cleaner, Gunk, power washing, and probably use of a
toothbrush and more brake cleaner will get the area acceptable. You might follow
up with compressed air delivered by a J-tube to remove dirt and little rocks lodged
up behind the solenoid. Haynes suggests the use of a sheet of cardboard over the
trans, up against the tunnel to keep grit from falling in from above. Dirt and
transmissions disagree.
Don't get any dirt into the solenoid when you replace it. This is a filthy area and it's
easy to do this. The plumbing internal to the solenoid unit, which has a right angle
turn at the valve seat, can plug up. You may have to pull the OD solenoid, rig it up
to the battery to turn it on and blow it out with WD40, carb cleaner, compressed
air, or any similar pressure source, preferably with a little straw to get down into
the holes.
[Editor] Two users reported that removing the solenoid and turning the engine over
seemed to pump enough oil through the recess to clean it out and enable
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operation. This is messy, though. [SML] Before re-installing the solenoid, clear the
oil passages in the transmission by slipping a tray under the tranny, starting the
car and quickly shifting the auto trans gear lever from P through R,N,D,2,1,P then
quickly off. About a 5 second process. A flood of trans oil will squirt out from the
car hopefully clearing any blockages.
[C. McGrew] My transmission was leaking fluid and was oil soaked from an engine
rear main seal leak. The solenoid rubber cap becomes brittle and then it's good
bye. Be sure to buy the two o-rings for the solenoid. Coat o-rings with plumbers or
silcone grease for sealing and ease of install. It's not that bad getting your fingers
in the correct position to replace the two bolts. Re-torque to 7-12 ft-lbs to tighten
the solenoid bolts.
Rusted Bolts. [James Souther] If the solenoid mounting bolts are rusted, the
lockwasher is only rusted to the solenoid flange and the bolt head, not in the
threads as the case is aluminum so PB Blaster or Kroil will help but not solve (no
pun intended). If you use penetrants, use starting fluid or brake cleaner to clean
off around the solenoid base before you start as both dirt and penetrants are not
good for the inside of the transmission. Second, free the solenoid wire cable and
the brackets before trying to loosen the bolts. This lets you get better access if you
flop that out of the way. If needed you can take the nut off the shift shaft input
and move it away, however, you need to hold the lever so you do not stress
against the transmission valve assembly inside. The lever goes on with a
rectangular notch. Third, attack the bolts which set very close to the solenoid body
and come out by hand after a turn or two. IMHE the original bolts seem way
overtight due to being threadlocked so what works is a quarter inch 6 pt socket
with extensions to get down on top of the bolts or a thin box end wrench and lots
of force. The posture is pulling the car and the wrench or ratchet together so you
can put enough force on it. In a dozen or so times, the bolts mostly "crack" loose.
When you get it out, check to make sure the old o-rings are not stuck on the
transmission flat. Finally, take heart, installation is a breeze compared to taking it
Eliminating the Overdrive Disabling Function at the Relay. [Bill Foster] If you
never ever use the overdrive switch to disable the OD, you may want it
permanently enabled. To bypass it, use a short jumper with 2 1/4 inch male
terminals inserted in the switched hot terminal to the solenoid terminal of the
overdrive relay. The wiring diagram is often on the relay.
Eliminating the Solenoid and the Manual Downshift System:
You can also pull the
solenoid entirely,
replacing it with a
metal plate, and
remove the ability to
use the button to
manually shift down
into third. See the link
below for IPD's solution
to solenoid troubles.
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[E. J. Ohler] Forget
about a new $150
solenoid and $50 relay:
take the solenoid out,
cut the wire off and cap
the end, grind a small groove between the center hole and aft hole in the solenoid
face, and reinstall to allow fluid to move and disable the solenoid as a solution to
solenoid troubles. Use a Dremel 1/8 inch grinding tool (the metal is hard so you
will use two) or a diamond bit. Clean the matching holes in the tranny using drill
bits the same diameter, but don't drop them into the transmission. Replace the
outer O-ring but not the inner where the groove passes through. From start to
finish this is a 3 hour job that saves you a lot of headaches. You don't need the
manual 4-3 downshift in most instances anyway.
Solenoid Quality Reports:
[Tip from Dan Marino] My recently-installed Scantech
OD solenoid failed. I discovered that the rubber top cap
(the part where the electrical wire attaches to the
solenoid) had totally split away from the metal solenoid
valve parts. Basically, the top blew off of the thing. The
result, massive transmission fluid leakage. My conclusion
is that this ScanTech overdrive solenoid suffers from
poor quality construction, cheap-o materials, and design
flaws. The next day I was able to pull an original Volvo overdrive solenoid from a
junker for a cost of $5.25. A quick comparison showed the Volvo part to be of
superior design, more metal, and less plastic/rubber.
Solenoid and Overdrive Removal. [Ken Crossner] For you
folks who wish their automatics were simply completely
automatic without any tendancy to fail and lose 4th
(especially during this gas crisis time), IPD came up with a
solution! They're selling a Solenoid Bypass Plate (product
code MD7071K - $39.95.) Remove the solenoid, cover the
hole with this plate, and you're left with a 4-speed automatic
transmission -- the 4th (OD) gear works normally, and you can dispense
completely with all the other components (relay, shifter switch, wiring, etc.).
Nothing left to fail, ever! You merely lose the ability to manually downshift into
third gear, which you probably never used much anyway. You can remove the
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overdrive relay to turn off the lamp permanently and remove the power to the
+12V lead to the solenoid.
[John Orrell] there is a almost free way of doing this. Remove the stock solenoid,
remove the inner O-ring and machine/grind a groove in the face of the solenoid
between the two small holes. Replace the outer O-ring (not exactly free, but
cheaper than 39.95) and reinstall the solenoid.
AW7X Diagnostic Notes
Governor Pressure Test. [Tip from Abe Crombie] The governor is best checked
with a gauge attached to the tap point on driver's side of trans on case just
forward of tailhousing joint. This plug is a 8mm X 1.0 bolt. The gauge fitting used
is an o ring sealed hollow bolt with a cross-drilled bolt that goes through fitting in
hose from the Volvo special tool gauge. You may be able to fashion something like
this. The gauge needs to be able to read 60 -70 psi at least. The pressure should
correspond more or less to the road speed once you get to 10 mph or above.
Approx 1 psi per each mph.
ZF22 Damage in Park. [Inquiry] I have a 1986 740 GLE. I took the vehicle for
emissions testing in March. Part of the test is to rev the car for several minutes
while they check the high idle (2500 rpm). My transmission started slipping badly
when I left, and lost all forward gears the next day. I replaced it with a junkyard
tranny (I know its a risk, couldn't afford a rebuild) and the car has run great for
about 3,000 miles. My tags have expired, so I went back for another emissions test
(it failed the first time). Unfortunately, it failed again, but this time, it would hardly
move. I made it about 1 mile, then had to be towed. I was told by a transmission
shop that the ZF 4HP22 transmission cannot be revved in park without causing
damage and that a bulletin went out to all emissions testing facilities. A dejanews
search found several old posts saying smog tests would kill this transmission,
something about after being in forward gears then put in park, some pressure is
still on the clutches and will wear out clutch pack A. This seems to apply to Volvos,
BMWs and Jags with the ZF 4HP22 transmissions. The emissions testing people
have called me 5 times since yesterday, they seem concerned and are having my
car towed to have the transmission checked. They will not admit to any bulletin,
but obviously seem concerned about liability. My question: does anyone have any
info on these transmissions? I have heard of a Volvo bulletin on this, and an EPA
bulletin (may be just California EPA, not sure). Bulletin numbers or a copy of the
bulletins would be great. I'd like some facts to present them with since they are
listening, but so far just have a little info from old newsgroup posts, and from a
conversation with a transmission shop.
[Response 1: Mark Aarabi] What you have heard and read is absolutely true. Yes,
there is a TSB out.(Volvo TSB 2525, 9/91, for all ZF-equipped 1985-88 740 nonturbos).. and Yes, there was a memo from EPD to all emission testing facilities
about this concern (at least here in Georgia). What state are you in and do you
have any idea what type of equipment they use for testing? The software on most
BAR97 equipment will automatically bypass the 2500 RPM section of the test on
these particular vehicles.
[Response 2: Bruce] Most all emissions center should be aware of this problem.
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Transmission. Automatic AW70 and ZF
Other cars have the same problem that use the ZF tranny. As the one post stated
the test machines will by-pass the rpm test with a ZF tranny. The emission shop
should replace your tranny. But getting them to admit fault and do it could be a
problem. For others reading this, 1985, 86 and 87 only 740's used the ZF tranny.
(Editor's Note: ZF-22 cars have P-R-N-D-3-2-1 on the shift quadrant and NO
overdrive button on the shifter.) Turbo models use the AW-71. For the above
model years, if the gear shift lever does NOT have an OD button you have a ZF
tranny. With an OD button you have the AW-71 tranny. One way to test the
emission on a ZF tranny is to raise the back wheels off the ground, put the car in
drive and rev it up to 2500 rpm for testing. In gear it will not do harm. In neutral
or park and revving, the tranny pump does not pump oil. I was told this by a
transmission repair center.
Volvo Technical Service Bulletin on This Problem:
[Editor's Note:Summary of Volvo TSB 2525, 9/91:] Before beginning the High Idle
Emission Test Sequence make sure the car is at operating temperature. Place
transmission into park and switch the ignition off for 30 seconds. Restart, but DO
NOT move the selector through the forward or reverse gears before or during the
test and DO NOT EXCEED 2000 RPM. The first stage of the test is at 1850 rpm for
30 seconds, the second stage is at normal idle for 30 seconds. If you fail the test
and have to do it again, then DO NOT proceed with the programmed catalyst
preconditioning test sequence. Abort the test, place the transmission into park,
precondition the catalyst at 1850 rpm for 4 minutes, then allow the engine to
revert to normal idle and check the tailpipe emissions. Under no circumstances
must you exceed 2000 rpm during any part of the test.
Reasons for Transmission Failure:
[Jim Bowers] Here is what I have learned from various inputs, some on Brickboard,
some from BMW related sources. The transmission apparently leaves some residual
pressure on the clutches when put in P and/or N. If the engine is revved in this
state the clutches get burned.
[Martin] I rebuilt a used ZF and learned some about the slipping #1 clutch pack,
too. The input shaft was originally sealed with metal rings which were prone to leak
and leave some pressure on the clutch pack during all conditions, causing it to fail
early. The rebuild kit (non oem) however contained redesigned teflon rings packed
with some information on the issue. During rebuild I also discovered there are
some other poor design issues in this tranny. Light alloy clutch cases which will
wear rapidly, some strange sealing designs between valve body/housing and in my
case also a pair of blown bearings. I used parts out of two trannies since the actual
ZF problem seems to be the horribly expensive hardware, making a complete swap
desirable if the worn out unit needs anything more than clutches/sealings. AW
trannies does seem to be better designs, without expensive failure spots like these
of the ZF.
ZF Preventive Maintenance:
[Fitz Fitzgerald] There are many people putting a lot of miles on ZF transmissions,
but the transmissions are more prone to failure than the AW trannys. A few words
of advice for preventive maintenance on ZFs:
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Transmission. Automatic AW70 and ZF
1. Do not rev the engine in Park or Neutral: this will tear one of the forward
clutch packs to pieces.
2. Change the fluid at the specified intervals and be sure to remove and clean the
pan before the first fluid change. Performing a fluid flush without first
removing the pan can break up some sediment in the bottom which will be
sucked up into the takeup and act like sand in the bearings and valve bodies.
Feel free to toss in a larger magnet before putting the pan back on.
3. Run synthetic trans fluid if you can afford it. Mobil 1 full-synthetic is worth the
improved longevity.
If the transmission fails, swap it for an AW.
ZF22 Fails; Swap for AW? [Inquiry:] The ZF4HP22 tranny in my '86 740 just
started spewing fluid from inside the bellhousing (1 pint/mile). Given the reputation
this tranny has, I'm undecided as to whether I should rebuild it or replace it with
an AW71. Has anyone done this swap?
[Response:] Do the swap. Any AW70 or 71 will work from 82-on. The basic
gearbox is the same, but some are better or stronger than others. If you're going
to buy one from a junkyard, get one from the latest years possible. (89-93 non
turbo, since they have a lock-up converter.) If you use an earlier gearbox, you will
need to plug the speedo drive hole in the output shaft housing. I don't remember if
the flex plate is the same or not, you may need that. The driveshaft is different. If
you order it from the boneyard, tell them you're doing the conversion. Remember
that the car didn't know what transmission it was going to get, so the interchange
is ''bolt in.'' I think if you get the necessary parts (with relatively low mileage) for
under $1000.00 you did all right.
[Response: Dick Riess] Actually quite easy to do:see the Auto Transmission
Conversion: ZF to AW FAQ file describing how to do this. . Best bet is contact
someone like Strandbergs in WI 800 448 5121 and they literally send you a good
used unit plus all parts. I did an 86 740 couple of years ago and works great. Here
are the parts you will need: transmission, cross member, transmission mount, drive
shaft front half, gear selector unit, relay for overdrive on AW unit, some wiring. Get
good wiring diagrams to help you out.
[Response: Kane] All 4-cylinder trannies bolt up fine, including pre-'86 240 series
ones. One difference is the speedo ... the pre- had a speedo gear at the rear
tailcone, where as the 740's and later 240's had an electronic pickup sensor at the
differential. That tailcone can be swapped with one that doesn't have the output
Transmission Removal:
Transmission Removal. [John Orrell] Don't consider trying to remove your
transmission with either a dedicated transmission jack or a $40 transmission
adapter for your floor jack from Harbor Freight or the like. Here are the steps to
remove your transmission:
1. Set parking brake and disconnect battery negative/earth
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Transmission. Automatic AW70 and ZF
2. Release kickdown cable at throttle pulley and remove dipstick
3. Use floor jack under the front suspension cross member... in the center.
4. Jack it up to maximum lift range of the jack and put quality jack stands under
the front factory jacking points. Don't use cheap or undersized stands.
5. Let it down on the jack stands.
6. Put floor jack under the center of the rear differential.
7. Jack up the rear end as far as the jack allows, make SURE that the car does
not rock the front jack stands forwards or backwards!
8. Put another set of jack stands under the rear factory jack points and let the
jack down.
9. Drain oil from transmission
10. Disconnect oil cooler lines from radiator - use a counter hold wrench at the
radiator to prevent damage. Also disconnect lines at transmission. You will
bathe in oil. Remove line holder at bellhousing (l -10mm bolt). Remove lines
from engine bellhousing.
11. Loosen nut holding filler tube - dipstick holder from oil pan. Once pan is
drained, put plug backs in and block holes vacated by lines and filler tube.
12. Disconnect shift levers from transmission. Two E clips.
13. Disconnect driveline at back of transmission and front of differential.
14. Support transmission with a transmission jack, safely secured to the tranny.
15. Remove center support bracket. Total of 6 bolts. You will need the plate for
mounting the new drive shafts.
16. Remove exhaust pipe support near the back of the transmission. Not on all
17. Remove nuts from exhaust pipe to manifold (3).
18. Remove bolts holding exhaust pipe to bellhousing.
19. Free exhaust pipe from exhaust manifold.
20. Remove aluminum engine support bracket under the engine. This binds engine
to bellhousing.
21. Remove 4 bolts holding torque converter to flexplate. You will need to
counterhold the flexplate.
22. Loosen and remove starter bolts.
23. Remove distributor cap and rotor. You don't want to crush it against the
firewall. Alternatively, support the engine using a hook at the rear connected
to an engine lift.
24. Remove transmission crossmember. Two bolts on each side and one nut
holding transmission to the crossmember. Remove the bolt from the
transmission - need to tap with a hammer once the crossmember is removed.
25. Remove all bellhousing bolts. The top bolts can be reached from above using a
19mm wrench.
26. Carefully pull transmission back until clear of bellhousing and lower. You will
probably take another transmission oil bath, especially if the torque converter
decides to come out. Best to cross wire in the torque converter to prevent it
from slipping out: wire from ear to ear of bellhousing portion on transmission.
Remove transmission from under the car.
27. Remove flex plate - loosen bolts in a cross pattern. For a counterhold to
secure the flywheel, install a very strong C clamp through the starter hole in
the block, squeezing on the front and back of the flywheel.
28. Mark or know the position of the flexplate on the crankshaft, as it prevents
timing problems later.
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Transmission. Automatic AW70 and ZF
Installation. This is generally the reverse, but position the torque converter and
orient the flex plate correctly on reinstallation. Remove and install new rear main
engine seal:see instructions for this as well as other items skipped in these
instructions. Torques on reinstallation include:
Fluid dipstick tube to pan nut: 90 Nm (66 ft-lb)
Torque converter to carrier plate bolts: 50 Nm (36 ft-lb), torqued alternately
in a cross pattern
Torque converter housing bolts to engine: M10 are 42.5 Nm (32 ft-lb); M12
are 72.5 Nm (52 ft-lb)
Center support: 26 Nm (20 ft-lb) tightened alternately in steps of 7 Nm (5 ftlb)
Oil pan bolts to transmission body: 5 Nm (3.5 ft-lb)
Coupling flange on output shaft: 45 Nm (34 ft-lb) using Loctite
Oil cooler connections on side of transmission: 25 Nm (18 ft-lb)
Bellhousing Bolt Removal. See the discussion in the Engine: Mechanical section.
Torque Converter Alignment on Transmission Reinstallation. [Inquiry] Why is
the shaft on the torque converter that goes into the transmission slotted on both
sides of the end of the shaft?
[Response: Chris Herbst] Those slots have to be aligned with the oil pump on the
inside (they fit over the extrusions or dogs inside the trans). If you don't line them
up you'll chew up the torque converter and the drive gear inside the transmission,
which basically means getting another transmission. In addition, your oil pump will
not engage. In other words, alignment on reinstallation is very important. See also
the notes on alignment related to engine rear seal installation.
[Jerry Andersch] When the torque converter is properly seated it should sit 1/2"
below the bell housing flange. If it's flush with it, it's not seated all the way. With
the tranny slightly angled up (bell housing higher than the tail)work the TC back
and forth until it seats, sliding down 1/2" of so below the bell housing flange. When
installing the tranny make sure the BH is slightly higher as you move the box into
place, so the TC does not slide forward and out of place. Bolting the autobox into
place with the TC not properly seated can damage the transmission.
Rebuild or Replace Information:
The transmission in my Volvo is fading and needs to be rebuilt. What should I do?
[Rob Bareiss] Not worth rebuilding. Good used ones are SO CHEAP that there's no
reason to pay $900 for a rebuild, vs. $250 for a junkyard trans. The downtime is a
lot less too- pull yours and chuck it, bolt in the new used one, 4 hours you're done.
Compared to 3 days on the bench waiting for the rebuild. [Rhys] The Aisin Warner
70 is an excellent trans, very long lived. A good used one is always an easier way
to go. The rebuild kit for soft parts is only about $150.00, but if you need any hard
parts, the cost goes up dramatically. And rebuilding one is a challenge the first
time. You'll need the factory manual, which covers the BW55-AW70 trans. Very
good publication, but pricey.
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Transmission. Automatic AW70 and ZF
Transmission Interchange? [Jay Simkin] In the 940s and most post-1989 740s,
the trannies used were made by Aisin-Warner. These units are very robust. Nonturbo cars usually had an AW70L or AW71L (L = locking torque converter) while
turbo-equipped cars came with the AW71 unit (non-locking torque converter). Look
for a used AW70, AW71 or 71L (depending of whether the car has a turbo or nonturbo engine). These AW units can come from a 740 or a 940. The 24-valve (6
cylinder) 960 series cars were equipped with the AW30-43 unit. The AW30-43 is
computer-controlled, and does not interchange with an AW70 or AW71 unit.
Replacement Tips. [Jerry Andersch/Others] See the FAQ section on rear engine
seal replacement for more information on removing and replacing the transmission.
Used Transmissions. [Marlin Mangels] When you buy a used transmission to
replace your failed unit, get one with pink (not brown) fluid to make sure you are
not acquiring a soon-to-fail unit. Buy one that comes with its torque converter.
Torque converters vary in application and matching the TC with the tranny may be
difficult if you don't have the original. Used transmissions may be sourced from
junkyards anywhere. Pay attention to model and lockup function on the
identification tag.
Pulling the Tranny. Best technique is to use a rented transmission jack. In my
experience, after trying to get the fill tube off without success I gave up and
removed the tranny with the pan and tube in place. It is possible to drop and
reinstall a new tranny with it still attached; just make sure you have someone
guide it up while you're doing it because it will get caught. On reinstallation, once
you get the tranny lined up make sure to use the rear of the tranny to push it into
place; this is the only way to do this. Attempting to force it in by putting the
mounting bolts in doesnt work out very well. If you have a problem getting it to
line up with the engine i suggest you get a floor jack from a friend and jack the
front of the engine up just a little (but not by much or you might cause damage in
areas not intended.) Don't tilt the tranny too far forward or your torque converter
will fall out. If you have to pull the pan off, be ready for a mess. Fluid will continue
to drip for a long time. You need a large pan to catch the dripping oil. If you plan
on re-using the kick-down cable, be sure to secure it as you remove the
transmission. I broke mine at the plastic fitting where the cable enters the
Torque Converter. The TC will pull straight out ... or fall out if you tilt the tranny
too far foward. I removed my replacement pick and pull convertor to replace the
main front seal. I let the TC drain into a clean coffee can to get all the old ATF out
of it. After replacing the seal and pouring some AFT into the converter it's very
important to seat the TC properly on the oil pump drive ... The converter should
slip onto the drive and seat below the edge of the bellhousing, not flush with it.
Turn it back and forth until it slips in to place. If it's not seated properly or slips
forward out of seat as you install the transmission in your Brick, the oil pump drive
will not be properly engaged and things will get chewed up when you start the
motor. A properly seated conveter will sit about 3/4" below (or back from) the front
edge of the bell housing.
Engine Rear Seal. Now is a perfect time to renew the engine rear seal, which
requires removal of the transmission.
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Transmission. Automatic AW70 and ZF
Parts Renewal. I removed the TC and then using a seal puller removed the front
main seal. Slathered a generous amount of ATF of the new seal and carefully
seated it so it was not cocked. Make sure you lube all new seals. I also replaced
the cross (selector) shaft seals,solenoid and cooler line o-rings, kickdown cable oring and kick down cable, pulled the pan and cleaned it and the pan magnet, pulled
the mesh filter screen and cleaned it, and replaced the pan gasket. Replaced the
rear bushing, oil seal, and gasket. I also put in new nylon shift linkage bushings
and overdrive solenoid o-rings. All this is a lot easier to do when the tranny's out
of the Brick ... and if done correctly will assure you not a drop of ATF will leak out
of your new autobox. On reinstallation, I replaced the kickdown cable. I filled the
new box with approx 8 Qts of Mobile 1 synthetic ATF and a dose of Lube Guard.
Transmission Rebuilding Instructions: Valve Body and Complete
Transmission. See Brad Wightman's illustrated FAQ description of the valve body
service in AW-7X series transmissions. Don't so this without the Volvo illustrated
OEM manual. For complete rebuilding instructions, see Kenny's detailed and lengthy
illustrated instructions in the FAQ file which has illustrations of valve body
components from the OEM manual.
AW Transmission Parts and Rebuild Technical Help . [Tip from Frank] The AW
(Aisin Warner .... Asia's version of Borg Warner) is the most common import tranny
out there from Toyota to Isuzu. There are several good service books, better than
Volvo's own technical publication. My suggestion is to call either of the two
suppliers below and ask for the best novice book they have (Trans Mart will even
give you the info to get it yourself if you wish, but Trans Star won't). Read the
book cover to cover before touching the tranny. I'd even go so far as to suggest
you get the service updates manuals from the same location. If you decide to
rebuild your unit, here are the best places in the United States for a transmission
kit and parts:
Trans Mart (division of ATC Distributing) phone# 800-633-3340 (they'll give
you a number that is closer to you). GREAT customer service
The next best is Trans Star 800-321-8830 (they're a little higher on parts &
their customer service is good.)
Volvo Maintenance FAQ for 7xx/9xx/90 Cars
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