4: Rear Axle

PART 4-1

GENERAL AXLE SERVICE

PART 4-2

REAR AXLE

PAGE

4-1

PART 4-3

SPECIFICATIONS

‘PAGE

4-19

4-6

PART

A

LI-I

GENERAL AXLE SERVICE

Section

1 Diagnosis and Testing

2 Common Adjustments and Repairs

Page

4-1

4-2

Section

3 Cleaning and Inspection

U

DIAGNOSIS AND TESTING

Certain rear axle trouble symptoms parts of the car. For this reason, are also common to the engine, drive line, transmission, tires, and other be sure that the cause of the trouble is in the rear axle before adjusting,

REAR AXLE TROUBLE DIAGNOSIS GUIDE

Page

4-4 repairing, or replacing any of the axle parts.

EXCESSIVE REAR AXLE

NOISE

ALL REAR AXLES’

/ j

Since gears are in mesh, some rear axle noise is normal. However, excessive noise often indicates the beginning of other troubles in the axle.

A road test can help determine whether the noise is being caused

by

trouble in the rear axle or in other parts of the car. Before road-test- ing the car, make sure that the tire pressures and the rear axle lubri-

cant level are normal. Then drive

the car far enough to warm the

axle lubricant to its normal operating temperature.

With the car stopped and the transmission in neutral, run the engine at various speeds. If the noise still exists during this test, it probably comes from the engine or the exhaust system.

To determine if the noise is being caused by the rear axle or the tires, drive the car over several different types of road surfaces. Smooth asphalt or black-top roads minimize tire noises. Tire noises may be eliminated by cross-switching the tires. Snow tires often cause noises not heard with conventional tires.

Noise caused by a worn or damaged wheel bearing is often loudest when the car is coasting at low speeds, and it usually stops when the brakes are gently applied. To find the noisy bearing, jack up each wheel and check each bearing for roughness while the wheel is rotat ing, provided that the car is equipped with a conventional differential.

If all possible external sources of noise have been checked and eliminated, and the noise still exists, road-test the rear axle under all four driving conditions:

1. Drive: Higher than normal

road-load power, where the speed gradually increases on level road acceleration.

2. Cruise: Constant speed opera tion at normal road speeds.

3. Float: Using only enough throttle to keep the car from driving the engine. Car will slow down very little load on rear axle gears.

4. Coast: Throttle closed

engine is braking the car. Load is on the coast side of the gear set.

Any noise produced by the side gears and pinions in the differential case will be most pronounced on turns. A continuous whine under a light load between 20 and

35

miles per hour indicates rough or brin

CONTINUED ON NEXT PAGE

U

4-2

GROUP 4-REAR AXLE

REAR AXLE TROUBLE DIAGNOSIS GUIDE Continued

EXCESSIVE REAR AXLE

NOISE

ALL REAR AXLES

nelled pinion bearings. If the tone

of drive, coast and float noise differs with speed and if the noise is very

EXCESSIVE REAR AXLE

BACKLASH

ALL REAR AXLES

Excessive backlash in the axle driving parts may be caused by worn

axle

shaft splines, loose axle shaft flange nuts, loose U-joint flange mountings, excessive backlash be-

DIFFERENTIAL CHATTERS

DIRECTED POWER ONLY

Before removing the "Directed

Power" differential

for overhaul,

change the lubricant as described in the following procedure and operate the car for 200 miles.

1. Operate the vehicle enough to thoroughly warm the rear axle lubricant.

2. Thoroughly clean the area around the rear axle housing cover.

3. Remove the housing cover bolts and cover. Drain the lubricant,

4. Rotate the wheels by hand to allow the lubricant in the unit to drain,

5. Syphon or wipe out all lubri-

058 rough and irregular; worn, rough or loose differential or pinion shaft bearings are indicated.

tween the drive pinion and drive gear, excessive backlash in the dif ferential gears, or bearings which are worn or out of adjustment.

cant that did not drain. Flushing

the unit with solvents is not rec ommended due to the undesirable

effect the solvents may have on

the new lubricant.

6. Clean the gasket surfaces. Install a new gasket, and install the cover and bolts.

7. Torque the cover bolts to specifications.

8. Refill with the specified lubri cant.

If the chatter is still evident after

200 miles of operation, remove and overhaul the "Directed Power" dif ferential.

AXLE WILL NOT DRIVE

WITH POOR TRACTION AT

ONE WHEEL

DIRECTED POWER ONLY

The pulling power of each rear wheel should be tested separately.

Place one wheel on good traction such as dry cement and the other wheel on ice, snow, mud, gravel, or grease. Try to drive the car either forward or backward.

To avoid

"break-away" of the good traction wheel, apply the throttle lightly. If the car does not move and the poor traction wheel spins, the parking

brake should be applied to cause a

slight drag. This light brake application should provide the resistance

0

COMMON ADJUSTMENTS AND REPAIRS

PINION AND RING GEAR

TOOTH CONTACT ADJUSTMENT

Two separate adjustments affect

pinion and ring gear tooth contact.

They are pinion location and back lash Fig. 1. Painting the ring gear the carrier housing to locate the pinion for correct contact with the ring gear. The original factory in stalled shim pack is of the correct thickness for a given original carrier and gear set assembly. In service, teeth with marking compound and rolling a pattern, as described under

"Inspection Before Disassembly of

Carrier" in Section 3, will indicate what adjustments should be made on a particular gear set.

shims should be added or removed from the original pack only as in dicated by the tooth pattern check

Fig. 2. Adding shims moves the pinion toward the ring gear; remov ing shims moves the pinion away from the gear Fig. I.

PINION LOCATION

Individual differences in machin ing the carrier housing and the gear set require a shim pack between the pinion rear bearing cup and

BACKLASH BETWEEN RING

GEAR AND PINION

The tooth pattern check also in dicates whether the ring gear should required to apply the clutch at the poor traction wheel. Now, the car should move. Turn the car around and test the opposite wheel. If either wheel continues to spin even with the light brake application, remove and overhaul the differential.

Do not test the "Directed Power" differential while one wheel is on

a jack. The unit could cause the car to jump off the jack. This could

also occur during "on car" rear

wheel balancing. Wheels should,

therefore, be balanced off the car.

be adjusted away from or toward the pinion to increase or decrease back lash between the gears. The shims installed behind the differential side bearings locate the differential case and ring gear assembly in the car rier housing. To increase the back lash between the ring gear and pin ion move ring gear away from pinion, remove the necessary shims from behind the bearing on the ring gear side of the differential case and install them behind the bearing on the pinion side of the case Fig.

1. To decrease backlash move ring gear toward pinion, remove the necessary shims from behind the bearing on the pinion side of the

059 case and install them behind the bearing on the ring gear side of the case.

PINION BEARING PRELOAD

Any load applied to the pinion exerts a great amount of end thrust on the pinion shaft. On pull engine driving rear wheels, the pin ion tends to "walk" away from the ring gear, and the rear bearing takes the thrust

Fig. 1. On coast rear wheels driv ing engine, the pinion tends to

"walk" toward the ring gear, and the front bearing takes the thrust. If this end-play or "walk" were al lowed, pinion and ring gear tooth contact would change every time the end thrust on the pinion changed.

The pinion, therefore, must he held firmly in one place zero end play to maintain cor rect tooth contact.

Any change in the pinion locating shim pack requires a corresponding change in the bearing preload shim pack Fig. 1. The bearing cups are fixed in the housing and the cones are fixed to the pinion shaft; there fore, if the rear bearing cup position were changed by adding or removing shims, not only would the pinion shaft move in or out, but the cones moving with the shaft would move into or out of their cups to increase or decrease tension. The preload shim pack must be changed to com pensate for this change of bearing cone tension against the cups.

For example, if a 0.002 inch shim

PART

4-I-GENERAL AXLE SERVICE

FIG.

i-Pinion and Ring Gear Tooth Contact Adjustments

4-3

a TOE CONTACT

TO CORRECT-INCREASE BACKLASH,

MOVE RING GEAR AWAY FROM PINION

B CORRECT CONTACT

Ic HEEL CONTACT

TO CORRECT-DECREASE BACKLASH,

MOVE RING GEAR TOWARD PINION

d

CONTACT AT EDGE OF TOOTH

TO CORRECT-MOVE PINION IN

TO WARD RING GEAR, THEN ESTABLISH

CORRECT BACKLASH.

e CONTACT AT BASE OF TOOTH

TO CORRECT-MOVE PINION AWAY

FROM RING GEAR, THEN ESTABLISH

CORRECT BACKLASH.

NCTE Contact patterns

Pattern b

to, ct,

d and

e

indicate Incorrect placement of shims and will result in

noise

and gear

foilure.

shows Correct contact

pattern.

The above ring geor

tooth

contact patterns would be

mode

under

Load

conditions only actual operation. Do ,,ot attempt to check a new installation for

correct

contact under No Load

con

d,tior,s.

TOOTH CONTACT WILL BE CORRECT AS SHOWN AT B IF SHIMS HAVE BEEN PROPERLY INSTAUED.

FIG.

2-Tooth Contact Pattern Check

E14 17-A

4-4

were removed from the locating shim pack to move the pinion 0.002

inch farther away from the ring gear, the rear bearing cup would move closer to the front bearing cup by 0.002 inch. As the pinion shaft and rear bearing cone shifted with the rear bearing cup, the front bear ing cone would move 0.002 inch out of its cup thus decreasing preload.

A 0.002-inch shim, therefore, must be removed from the preload shim pack also so that the front bearing cone can move the 0.002 inch back into its cup to restore the original preload.

GROUP 4-REAR AXLE

Similarly, if a 0.002-inch shim were added to the locating shim pack to move the pinion 0.002 inch closer to the ring gear, the rear bear ing cup would move farther away from the front bearing cup by 0.002

inch. As the pinion shaft and rear bearing cone shifted rearward with the rear bearing cup, the front bear ing cone would move 0.002 inch farther into its cup thus increasing tension. A 0.002-inch shim, there fore, must be added to the pre load shim pack also so that the front bearing cone will move the 0.002

inch out of its cup to relieve the

U

CLEANINGAND INSPECTION

INSPECTION BEFORE

DISASSEMBLY OF CARRIER

The differential carrier should be inspected before any parts are re moved from it. The checks given in the following procedure can help to find the cause of the trouble and to determine the corrections needed.

1. Place the housing assembly in a holding fixture, tool 4005 as shown in Fig. 3.

2. Thoroughly clean the housing and cover assembly, and then remove the cover-to-housing bolts.

3. Using a suitable solvent, clean the lubricant from the internal work ing parts and visually inspect the parts for wear or damage. Rotate the gears to see if there is any rough ness which would indicate defective bearings or chipped gears. Check the gear teeth for scoring or signs of abnormal wear.

4. Set up a dial indicator Fig. 4, and check the backlash between the drive gear and pinion at four equally spaced points around the drive gear.

Backlash should be within specifica tions.

5. If no obvious defect is noted, check the gear tooth contact. Paint the gear teeth with suitable gear marking compound, such as a paste made with dry red lead and oil. A mixture that is too wet will run and smear. Too dry a mixture cannot be pressed out from between the teeth. Wrap a cloth or rope around the drive pinion flange to act as a brake.

Rotate the ring gear back and forth use a box wrench on the ring gear attaching bolts for a lever until a clear tooth contact pattern is obtained.

Certain types of gear tooth contact patterns on the drive gear indicate incorrect adjustment. Noise caused by incorrect adjustment can often be corrected by readjusting the gears as outlined in Section 2.

Typical patterns and the necessary correc tions are shown in Fig. 2.

6. Gear tooth runout can some

times be detected by an erratic pat tern on the teeth. However, a dial indicator should be used to measure the runout of the back face of the

FIG.

3-Axle Housing

AssenbIy in Holding Fixture

FIG.

4-Backlash Check

060 tension and restore original preload.

DETERMINING THE SHIM

PACKS

To make any of the foregoing ad justments, the differential case, drive pinion, and pinion bearings will have to be removed from the housing as outlined under "Disassembly" in

Part 4-2. The correct thickness for the four shim packs shown in Fig.

1 can then be determined by follow ing the "Installation of Pinion, Bear ings, and Differential Case" proce dure outlined under "Assembly" in

Part 4-2.

Tool-4201-C

FIG.

5-Ring Gear Runout Check

ring gear, as shown in Fig.

5.

With the indicator at zero setting, revolve the ring gear one revolution and note the total runout. If the total indicator reading exceeds specifica tions, it may indicate a loose ring gear or a sprung differential case or housing. Disassemble the carrier and replace necessary parts a in dicated in Part 4-2, Section 4.

7. Check the clearance between

the side bearing caps and bearing cups. If the clearance is 0.003 inch or more, it could indicate that the bearing is turning in the housing.

Visually check to determine that the cap is properly seated against its mating surface on the housing. If the clearance exists with the cap properly seated and the bolts prop erly torqued, check the mating sur faces of the housing and caps for damage. Replace the housing and/or caps as necessary.

INSPECTION AFTER

DISASSEMBLY

Thoroughly clean all parts Fig.

6 except wheel bearings in clean sol

061

TI-tRUST

PART

4-1--GENERAL AXLE SERVICE 4-5,

NUT

E1390-A

FIG.

6-Rear Axle Disassembled

vent, and dry them with compressed air.

Inspect the parts for defects.

Clean the inside of the carrier before rebuilding it. When a scored gear set is replaced, the axle housing should be washed thoroughly and steam cleaned. This should he done only after the axle shafts, wheel hearings, and seals are removed from the housing. Inspect individual parts as outlined below.

GEARS*

Examine the pinion and ring gear teeth for scoring or excessive wear.

The pattern taken before disassembly should be helpful in judging if gears can he re-used.

Worn gears cannot he rebuilt to correct a noisy condi tion. Gear scoring is the result of excessive loading or the use of in correct lubricant. Scored gears can not he re-used.

Examine the teeth and thrust sur faces of the differential gears. Wear of splines, thrust surfaces, or thrust washers can contribute to excessive drive line backlash.

BEARING CUPS AND CONE

AND ROLLER ASSEMBLIES

Check the hearing cups for rings, scores, galling, or excessively worn wear patterns.

Pinion cups must be solidly seated. Check by attempting to insert a 0.0015-inch feeler be tween these cups and the bottoms of their bores.

When operated in the cups, cone and rtller assemblies must turn with out roughness. Examine the roller ends for wear. Stepwear on the roller ends indicates the hearings were not preloaded properly or the rctllers were slightly misaligned.

If inspection reveals either a de fective cup or a defective cone and rolier assembly

both parts

should be replaced to avoid early failure.

U-JOINT FLANGE

Re sure that the ears of the flange have not been damaged in removing the drive shaft or in removing the flange from the axle. The end of the flange that contacts the oil slinger as well as the flat surface of the pinion nut counterhore must he smooth.

Polish these surfaces if necessary.

Roughness aggravates backlash noises, and causes wear of the slinger and pinion nut with a resultall loss in pinion hearing prcload.

CARRIER HOUSING

Make sure that the dillercrttial hearing bores are smooth and that the threaded holes are not damaged.

Remove any nicks or burrs from the mating surfaces of the carrier hous ing.

DIFFERENTIAL CASE

Make sure that the hubs where the bearings mount are smooth.

Carefully examine the differential case bearing shoulders, which may have been damaged when the bear ings were removed. The bearing as semblies will fail if they do not seat firmly against the shoulders. Check the fit free rotation of the differ ential side gears in their counterbores.

DIRECTED POWER

DIFFERENTIAL

Inspect all parts, particularly the spring plates and discs, the clutch plates and discs, the plate surfaces of the case halves, and the side gear rings for excessive wear or scoring

Part 4-2, Fig.

23.

Replace any parts that are worn or damaged.

If one or more of the plates or discs in a clutch pack on one of

the sides need replacing, the entire stack of plates and discs on that side should be replaced.

4-6

PART

REAR AXLE

Section

1

Description and Operation

2 In-Car Adjustment and Repair

Page

4-6

4-8

0

DESCRIPTION AND OPERATION

Section

3

Removal and Installation

4 Major Repair Operations

RING GEAR

PINION

062

Page

4-10

4-1 1

REAR

WHEEl. BEARING

T

DRIVE PINION

TAPERED PINION

BEARINGS

£1410-A

FIG.

i-Rear Axle Assembly

CONVENTIONAL AXLE

DESCRIPTION

The rear axle is of the integral carrier-housing, hypoid gear type, in which the centerline of the drive pinion is mounted below the center line of the ring gear Fig? 1.

The integral pinion gear and shaft is supported by two opposed tapered roller bearings which are assembled in the forward side of the carrier housing. Pinion locating shims, in stalled between the rear bearing cup and the cup seat, control the drive pinion depth adjustment. The pinion bearing preload is controlled

by shims located between the pin

ion front bearing and the shoulder on the drive pinion shaft.

The differential case assembly is supported by two opposed tapered roller side bearings and cups, which are retained in the housing by removable caps. Shims, installed between each differential side bear ing and the shoulder on the case, perform three functions: they take up the differential case side clear ance; they adjust the backlash be tween ring gear and pinion; and they establish differential side bear ing preload.

A cover on the rear of the carrier housing provides access for inspec

063 tion, removal and installation of the differential assembly and drive pin ion. A metal tag, stamped with the gear ratio plus the number of teeth on the ring gear and pinion, is se cured to the housing by one of the cover bolts.

Cars equipped with "Directed

Power" differential assemblies will have an additional metal tag iden tification attached to one of the cover bolts.

Ball bearing assemblies rear wheel bearings are pressed onto the outer ends of the axle shafts and set in the outer ends of the axle hous ing. These bearings support the semifloating axle shafts at the outer ends.

The inner ends of the shafts spline to the differential side gears. Bearing retainer plates hold the shafts in the housing. The axle shafts are equal in length and are, therefore, interchangeable.

OPERATION

The rear axle drive pinion receives its power from the engine through the transmission and drive shaft.

The pinion gear rotates the differen tial case through engagement with the drive gear, which is bolted to the case outer flange.

Inside the case, two different pinion gears are mounted on the differential pinion shaft which is pinned to the case.

These pinion gears are engaged with the side gears, to which the axle shafts are splined. Therefore, as the differential case turns, it rotates the axle shafts and rear wheels. When it is necessary for one wheel and axle shaft to rotate faster than the other, the faster turning side gear causes the pinions to roll on the slower turning side gear to allow differential action between the two axle shafts.

‘DIRECTED POWER" AXLE

DESCRIPTION

The "Directed Power" axle is the same as the conventional axle with respect to the ring gear and pinion the bearings, the housing, and the axle shafts. The difference is in the differential assembly.

The differential is of a two-piece case design Fig. 23. Each case half

PART 4-2-REAR

AXLE

has an identical clutch assembly which connects one of the axle shafts directly to the case half as driving conditions demand.

Each clutch pack consists of five steel plates set between the case and the side gear ring. The two outer plates and the center plate are locked to the dif ferential case half by external lugs.

The remaining two plates discs have internal spline teeth which lock to the splined huh on the side gear ring. The external lug plate and the spline disc plate that are located next to the case half are spring plates, which are installed with the convex bowed side against the case. The side gear ring is internally splined to the axle shaft and acts as a pres sure plate against the clutch pack.

Unlike the single pinion shaft of the conventional unit, the two pin ion mate shafts are not rigidly at tached to the differential case, nor are they attached to each other. At both ends of the mate shafts, there are two flat surfaces so arranged that they form a "V" which mates with corresponding "V" shaped surfaces ramps cut in the shaft openings of the differential case.

OPERATION

The "Directed Power" axle has a power flow identical to the coniven tional rear axle, plus a more direct power flow which automatically takes effect as driving conditions demand.

This more direct power flow is from the differential case to each axle shaft through clutches.

The mate shafts are assembled in the case with enough clearance so that when the case tries to rotate the mate shafts and the mate shafts resist rotation, they will be forced to hear against one side of their "V" ramps.

Since the two "V" ramps of one mate shaft point in a di rection opposite to that of the two ramps of the other mate shaft.

the two shafts with their pinions will be forced apart as they resist rotation. This mate shaft movement compresses the clutch pack through the pinion gears and side gear rings.

When the differential case rotates in the opposite direction, the mate shafts will be forced to bear against

4-7

the opposite side of their "V" ramps and will again be forced apart to apply against the clutch packs. There fore, since the ramps are "V" shaped, the clutches will apply during either forward or reverse operation. Like wise, the clutches will apply whether the power flow is from the differen tial case to the axle shafts, or from the axle shaft to the differential case.

The amount of compression on the clutch plates will be proportion ate to the load applied to the dif ferential case and the resistance to turning offered by each mate shaft.

For example, if the car is driven straight ahead and the traction or load on both wheels is equal, both mate shafts will give equal resistance to the rotating differential case and will thus bear against their respective ramps with equal force. This equal movement of the mate shafts will cause them to exert equal pressure against both right and left-hand clutch packs. Both axle shafts will, therefore, be locked directly to the case with equal force.

Clutch application prevents mo mentary spinning of one of the wheels when it leaves the road be cause of a bump, or encounters poor traction because of a slippery road.

Under these conditions, even though the traction load is relieved on the one wheel, the acceleration load is simultaneously applied to the dif ferential case as the engine tries to spin the wheel.

When the rear axle is in a turn, the appropriate clutch releases auto matically to allow normal differ ential operation as required. In the straight ahead position, the differ ential case is driving both wheels and thus applies an equal load against both mate shafts. Since both mate shafts offer resistance to this load, both clutches are applied. On a turn, however, the outside wheel turns faster than the inside wheel.

The outside wheel, instead of being driven by the case, now tends to drive the case. With the power thus relieved, the differential case releases its load against the outside wheel mate shaft which, in turn, releases its pressure against the outside wheel clutch pack. With the clutch released, normal differential action will take effect.

4-8 GROUP 4-REAR AXLE

fl

IN-CAR ADJUSTMENT AND REPAIR

REAR AXLE SHAFT, WHEEL

BEARING, AND OIL SEAL

REPLACEMENT

Too!-.- 4235-C

The rear axle shafts, wheel bear ings and oil seals can be replaced without removing the axle assembly from the car.

1. Remove the wheel and tire from the brake drum.

2. Remove the Tinnerman nuts that secure the brake drum to the axle shaft flange, and then remove the drum from the flange.

3. Working through the hole pro vided in the axle shaft flange, re move the nuts that secure the wheel bearing retainer to the axle housing

Fig. 2.

4. Pull the axle shaft assembly out of the axle housing Fig. 3. Install

one nut to hold the brake backing plate in place after the

axle

shaft is removed.

5. Check the bearing for smooth free rotation. Check the axle shaft splines for burrs, wear or damage.

Replace worn or damaged parts.

6. If the rear wheel bearing is to be replaced, loosen the inner retainer ring by nicking it deeply with a cold chisel in several places Fig. 4.

It will then slide off easily.

7. Press the bearing from the axle shaft with the tool shown in Fig.

5.

8. Inspect the machined surface of the axle shaft and the axle hous ing for rough spots or other irregu larities which would affect the seal ing action of the oil seal. Carefully remove any burrs or rough spots.

9. Lightly coat the wheel bearing bores with ball joint grease.

10. Place the retainer plate on the axle shaft, and press the wheel bear ing on the shaft with tool 4621-A as shown in Fig. 6.

Tool-

TSOTIOOC

FIG.

3-Axle Shaft Removal

£1032-C

11. Press on a new wheel bearing retainer ring with tool 4621-A. Do

not attempt to press on both the wheel bearing and retainer ring at the same time.

12. Whenever a rear axle shaft is removed, the oil seal must be

replaced. Remove the seal with the tool shown in Fig. 13.

for

13. Soak new

seals in SAE 10 oil

½

hour before use. Install the new seal with tool 4245-B as shown in Fig. 14. Wipe a small amount of an oil resistant sealer on the outer edge of the seal before it is installed.

Do not put sealer on the sealing

lip. Install the seal with its sealing lips toward the axle housing.

14.

Place a new gasket on each side of the brake backing plate, and then carefully slide the axle shaft into the housing so that the rough forging of the shaft will not damage the oil seal. Start the axle splines into the side gear, and push the shaft in until the bearing bottoms in the housing.

064

Tool-.1225-DA

412-A

FIG. 5-Rear Wheel Bearing

Removal

15. Install the bearing retainer plate and the nuts that secure iL

Torque the nuts to specification

Fig.

2.

16.

Install the brake drum arid the drum retaining nuts.

17. Install the wheel and tire on the drum.

DRIVE PINION OIL SEAL

REPLACEMENT

The drive pinion oil seal can be replaced without removing the rear axle assembly from the car. Soak the new seal in SAE 10 oil for ½ hour before use.

1. Raise the car on a hoist, or the rear of the car on a suitable jack.

E141 1-A

FIG. 2-Wheel Bearing Retainer

Plate Removal or Installation

El 357-A

FIG. 4-Wheel Bearing Retainer

Ring Removal

FIG. 6-Rear Wheel Bearing

Installation

065

PART 4-2-REAR

AXLE

TooI-4858- B

4-9

11

ll

I

FIG. i-Pinion Shaft Nut Removal or Installation-Axle in Car

2. Remove the retaining bolts and washers, and then remove the bump er, bracket, and spacers from the housing.

3. To maintain proper drive line balance, the drive shaft should he installed in its original position. To insure proper installation at assem bly, make scribe marks on the drive shaft rear end yoke and the axle

U-joint flange Fig. 12. Also, make chalk marks on the drive shaft front slip yoke and the transmission ex tension housing.

4. Disconn..ect the rear end of the drive shaft by removing the U-joint bearing caps that hold the spider to the axle U-joint flange.

Be careful

FIG. 9-Pinion Shaft Oil Seal

Removal

to avoid dropping

the loose

uni versal joint bearing cups. Slide the drive shaft forward, and remove it from the transmission extension housing. install tool 7657-J in the transmission housing to prevent leak age.

5. While holding the flange with tool 4851-K, remove the pinion shaft nut Fig.

7.

6. Clean the carrier-housing around the oil seal. Place a drain pan under the seal, or raise the front of the caf higher than the rear.

7.. The U-joint flange removing tool 4858-D must he modified to fit the larger 1961-64 U-joint flange.

This can be easily accomplished by drilling two additional 3/s-inch diam eter holes through the flat plate portions of the tool to correspond to the opposing diagonal holes in the flange. See Fig.

8 for drilling dimen sions.

8. Use reworked tool 4858-D to re move the U-joint flange from the drive pinion, as shown in Fig. 8. Re move the dust deflector if damaged.

9.

Remove the pinion shaft seal assembly using tool 1l75-AE, as shown in Fig. 9.

TooI.-4676

FIG. il-U-Joint Flange

Installation on Car

10. Inspect the parts. Replace any that are worn or damaged.

11. Clean the pinion oil seal seat.

Coat the outer edge of the new seal with a small amount of oil resistant sealer.

Do not put sealer on the

sealing lip. Drive the seal into the housing, using the tool shown in

Fig.

10.

12. Start a new dust deflector over the U-joint flange and drive the de flector into position on the flange as shown in Fig. 38.

13. Coat the inside of the U-joint flange with specified lubricant, and press the flange into position with tool 4858-B as shown in Fig. 11.

14. Remove the flange installing tool, and install the pinion shaft washer and nut. While holding the flange with the tool shown in Fig.

7, torque the pinion shaft nut to specifications.

15. Remove tool

7657-I

from the transmission extension housing. In stall the drive shaft to the transmis

FIG. 8-U-joint Flange Removal

-Axle in Car

FIG. lO-Pinion Shaft

Oil

Seal

Installation

END YOKE

.

. .

FLANGE

--

DRIVE SHAFT

i-..

-

/

-

‘

..."i.

r’

-.

-

:--

-

SCRIBE MARKS

‘BEARING CAP

E1418-A

FIG. l2-Drive Shaft-to-Axle

U-Joint Flange Connection

4-10

sion, so that the chalk marks on the slip yoke and the transmission extension housing are aligned,

16.

Position the drive shaft to the axle U-joint flange, aligning the scribe marks made on the drive shaft rear end yoke and the axle U-joint

GROUP 4-REAR AXLE

flange during the removal procedure

Fig.

12. Connect the shaft to the flange by installing the U-joint bearing caps that hold the spider to the flange. Install the bearing cap retaming bolts and torque to specifications.

U

REMOVAL AND INSTALLATION

REAR AXLE HOUSING

ASSEMBLY

REMOVAL

1. Raise the car on a hoist or the rear of the car on a suitable jack.

Place a jack stand under each side, at the rear of the spring hangers.

2. Lower the car until the weight is supported by the jack stands.

3. Drain the axle housing by loosening the rear cover bolts.

4. Remove the retaining bolts and washers, and remove the bumper, bracket and spacers from the hous ing.

5.

To maintain proper drive line balance, the drive shaft should be installed in its original position. To insure proper installation at assem bly, make scribe marks on the drive shaft rear end yoke and the axle

U-joint flange Fig. 12. Also, make chalk marks on the drive shaft front slip yoke and the transmission ex tension housing.

6. Disconnect the rear end of the drive shaft by removing the two

U-joint bearing caps that hold the spider to the axle U-joint flange.

Be careful to avoid dropping the loose universal joint bearing cups.

Slide the drive shaft forward, and remove it from the transmission extension housing.

Install tool 7657-J in the transmission housing to prevent leak age.

7. Remove the two rear wheel and tire assemblies.

8. Remove the Tinnerman nuts that secure each brake drum to the axle shaft flange, and then remove the drum from the flange.

9. Working through the hole pro vided in each axle shaft flange Fig.

2, remove the nuts that secure the wheel hearing retainer to the axle housing.

Pull each axle shaft and hearing assembly out of the axle housing using the tool shown in

Fig. 3.

10. Remove both wheel hearing oil seals Fig. 13.

11. Disconnect the rear shock ah sorbers from the mounting studs on the axle housing.

12. Remove the brake line-to-axle housing retaining clips and the re taining bolt holding the junction block to the axle housing.

13. Remove the parking brake

cable retainers from the U-bolts.

14.

plates body.

Remove the brake backing and wire them to the under

Do not disconnect the brake lines.

15. Remove the axle U-bolt re taining nuts.

16. Remove the U-bolts, the spring center mounting, insulator retainers and the insulators.

17. Remove the axle housing as sembly.

INSTALLATION

1. Clean the axle housing and shafts using kerosene and swabs. To avoid contamination of the grease in the sealed ball bearings, do not allow any quantity of solvent di rectly on the wheel bearings.

If the axle housing is being re placed, disassemble the drive pinion and differential case assembly from the old housing and assemble them in the replacement housing as des scribed in Part 2-2, Section 4. Re move the bolts that retain the brake backing plate and wheel bearing re tainer from the old housing flanges.

FIG. 13-Rear Wheel Bearing

Oil Seal Removal

066

17. Install the spacers, bumper bracket, and bumper on the hous ing, and secure with the retaining bolts and lockwashers.

18.

Check the lubricant level, and add whatever amount of specified lubricant is necessary. Lower the car.

Position the bolts in the replacement housing flanges.

2. Soak two new rear wheel bear ing oil seals in SAE 10 oil for ½ hour before installation.

Wipe a small amount of an oil resistant sealer on the outer edge of each seal before it is installed. Do not put

sealer on the sealing lip. Install

the oil seals in the ends of the rear axle housing with the sealing lip toward the housing Fig. 14.

3. Position the rear axle housing on the rear springs. Position the spring center mounting upper and lower insulators and retainers, the shim wedge, and the U-bolts.

4. Install the U-bolt retaining nuts and torque to specifications. Make sure that the spring lower insulator contacts the upper retainer.

5. Install the brake backing plates with new gaskets on the axle hous ing flanges.

6. Connect the parking brake cables to the U-bolts with the hook type retainers.

7. Install the junction block on the axle housing and secure with the retaining bolt. Position the brake line to the axle housing, and secure with the retaining clips.

8. Raise the rear axle housing and springs enough to allow connecting the rear shock absorbers to the

E14 14-A

FIG. 14-Rear Wheel Bearing

Oil Seal Installation

067

mounting studs on the axle housing.

Install the washers and nuts on the studs and torque to specifications.

9. Install the two axle shaft assem blies in the axle housing. Carefully slide each axle shaft into the housing so that the rough forging of the shaft will not damage the oil seal. Start the axle splines into the side gear, and push the shaft in until the bear ing bottoms in the housing.

10. Install the hearing retainer plates and the nuts that secure them.

Torque the nuts to specifications

Fig.

2.

PART 4-2-REAR AXLE

ii. Install the brake drums and the Tinnerman drum retaining nuts.

12. Install the wheel and tire as semblies on the drums.

13. Remove tool 7657-i from the transmission extension housing.

In stall the drive shaft to the transrnis sion, so that the chalk marks on the slip yoke and the transmission extension housing are aligned.

14.

Position the drive shaft on the axle U-joint flange, aligning the scribe marks made on the drive shaft rear end yoke and the axle U-joint

4-11

flange during the removal procedure

Fig. 12. Connect the shaft to the flange by installing the U-joint bear ing caps that hold the spider to the flange. Install the bearing cap re taining bolts, and torque to specifica tions.

15. Install the spacers, bumper bracket, and bumper on the housing and secure with the retaining bolts and lock washers.

16.

Fill the rear axle with specified lubricant.

Remove the jack stands and lower the car.

MAJOR REPAIR OPERATIONS

DISASSEMBLY

Mount the axle housing in the holding fixture tool 4005

Fig.

3,

Part 4-1, and perform the "Inspec tion Before Disassembly of Carrier" as explained in Part 4-1, Section 3.

Then disassemble the carrier as out lined in the following procedures.

REMOVAL OF

DIFFERENTIAL CASE,

PINION, AND BEARINGS

1. Remove the attaching bolts and the differential side bearing caps

Fig.

15.

Note the identification marks stamped on the bearings and housing for proper assembly.

2. Install the carrier spreader so that the dowels on the tool enter the openings in the housing

Fig.

16.

Tighten the hold-down clamp screws.

3. Release the wing nuts on the holding fixture, and spread the car rier housing by rotating the turnbuckle on the spreading tool. Spread

BEARING CAP LOCATING MARKS

BOTH LETtERS HORIZONTAL

CLAMP SCREW

Carrier Spreader

-

4000-C

*DOWEL

FIG. l6-Spreading Carrier

Housing

the housing until the differential as sembly can be forced out with a pry bar or long screwdriver. Do not

spread the housing more than

0.020 inch to remove the differen tial. Loosen the spreader turnbuckle immediately after lifting out the differential assembly to prevent springing the housing.

Place each differential bearing cup with its respective bearing for proper assembly.

4. Remove the spreader tool, and turn the housing in the holding fix ture so that the drive pinion shaft is in a vertical position. Remove the nut from the pinion shaft as shown in Fig. 17.

5. Remove the U-joint flange from the pinion shaft using the modified tool shown in Fig. 8.

6. Turn the housing in the hold ing fixture so that the drive pinion is in a horizontal position, and then remove the pinion shaft oil seal with the tool shown in Fig.

9. Lift out the gasket and slinger.

7. Turn tool 4201 onto the pinion shaft threads and drive against the tool until the pinion shaft and rear bearing are loosened from the hous ing Fig. 18. Remove the tool from the pinion shaft, withdraw the pin ion and rear bearing assembly from the rear of the housing, and remove the front bearing and preload shims from the front of the housing. Tie all

the

shims

together for

assem bly.

Record the thickness of the

shims in

case they should be

lost.

FIG. 15-Differential Bearing

Cap Locating Marks

E1352-A

FIG. li-Pinion Shaft Nut

Removal

1

Tool- 4201

FIG. l8-Pinion and Bearing

Assembly Removal

E1383-A

4-12

FIG.

l9-Pinion Rear Bearing

Cup Removal

8. Remove the pinion rear bearing cup as shown in Fig. 19. Remove the pinion locating shims and tie them together. Record the thickness of

the shims in case they should be lost.

9. With the forward end of the housing up, remove the pinion front bearing cup Fig. 20.

10. If necessary, the pinion rear bearing may be pressed off the drive pinion. Use tool 4621-BA.

If inspection before disassembly showed excessive ring gear runout, do not proceed to the disassembly of the differential case at this point. First, determine which parts

should be replaced differential case, bearings, or ring gear as explained under "Parts Repair or Replacement" in this section.

GROUP 4-REAR AXLE

CONVENTIONAL

DIFFERENTIAL CASE

DISASSEMBLY

1. Position the differential case in

the holding fixture, locate the fingers

of the puller tool in the

cast recesses

of the differential case, and pull one

of the differential side bearings Fig.

21.

Tie the shims together for assembly and label "ring gear side" or "pinion side." Record the thickness of the shims in case they should be lost.

-

2. Reverse the differential case in the holding fixture,

and remove the seconcL side bearing and shim pack as directed in step 1.

3. Remove the ring gear-to-differ ential case bolts, and remove the gear from the case.

4. With a punch, drive out the dif ferential pinion shaft lock pin. Re move the differential pinion shaft, pinions, and thrust washers. Remove the side gears and thrust washers.

Refer to Fig. 6, Part 4-1.

"DIRECTED POWER"

DIFFERENTIAL CASE

DISASSEMBLY

1. Mark the differential case

halves for correct alignment at as sembly. See the "Case Markings" in

Fig.

22.

2. Mark one end of each mate

shaft exactly as shown in Fig. 22 so that the "V" shaped end of each shaft will match the same "V" ramp in the case when the unit is assem bled.

"‘TooI-4ó28-B

E1385-A

FIG. 20-Pinion Front Bearing

Cup Removal

FIG. 2l-Differential Bearing

Removal

068

FIG. 22-Alignment Marks for

Proper Assembly

3. Place the assembly in holding fixture 4205-B shown in Fig. 21. If

the side bearings and/or ring gear do not require replacement, skip steps 4 and/or 5 and proceed with step 6.

4. Using the puller tool shown in

Fig. 21, remove one of the differen tial side bearings.

Tie the shims together for assembly, and label

"Ring Gear Side" or "Pinion Side."

Record the thickness of the shims in case they should be lost. Re verse the differential case in the fix

ture, and repeat the procedure for the opposite side bearing and shims.

5. Remove the ring gear-to-differ

ential case bolts and remove the gear from the case.

6. Loosen but do not remove the eight bolts that hold the differen tial case halves together.

Remove the differential case from the holding fixture and set the case on the bench with the ring gear half of the case

down as in Fig.

22.

7. Remove the case attaching.’bolts and the cover half of the case. Re move the upper clutch plates and discs, side gear ring, side gear, and upper mate shaft and pinions Fig.

23. Keep these parts with the cover half of the case so that they will be installed in their original posi tions during assembly.

8. Remove the corresponding parts

from the ring gear half of the case

Fig. 23, and keep the parts with

the ring gear half for proper assem bly.

PARTS REPAIR OR

REPLACEMENT

Clean and inspect all the parts as outlined in Part 4-1, Section 3. Be fore assembling the rear axle, repair or replace all parts as indicated by the inspection.

069

PART 4-2-REAR AXLE

PLATE

SIDL GEAR

RIN2,

DIFFERENTIAL

SIDE GEARS

FRICTION CI

SIDE GEAR

RING

4-13

CLU H DISC

FRICTION CLUTCH

CASE

RING GEAR FLANGE HALF

COVER HALF

E1391-A

FIG. 23-

"Directed Power" Differential- Disassembled

The principal replacement opera tions are covered in the following procedures.

All other repair or re placement operations are performed during "Cleaning and lnspection

Part 4-1, Section 3, or during the

"Assembly" procedures in this seclion.

DRIVE PINION AND RING

GEAR SET

When replacing a ring gear and pinion, note that the original factory installed pinion locating shim is ol the correct thickness to adjust for individual variations in both the car rier housing dimension and in the original gear set dimension. There fore, to select the correct shim thick ness for the new gear set to he in stalled, follow these steps:

1.

Measure the thickness of the

original pinion locating shim

with

a micrometer.

2.

Note the shim adjustment num ber on both the old pinion and the new pinion.

Each pinion uear is marked with an adjust iiien

I n u niber such as the

---

I markinu in Hg. 24.

3. Refer to the table in Part 4-3 for the correct amount of shim thick ness change.

The amount that is shown under the new pinion shim adjustment number and in line with the old pinion number is the amount of change that should be made to the original shim thickness.

II the old pinion is marked ±4, for example, and the new pinion is marked -2, the table indicates that

0.006 inch of shim stock should be added to the original shim pack.

If the original shim pack was lost or if a new axle housing is being in stalled, substitute a nominal

0.030

inch shim for the original, and re peat the foregoing steps for a trial build-up. If any further shim change is necessary, it will be indicated in the tooth pattern check.

A new ring gear and pinion should always be installed in an

MATCHED SET IDENTIFICATION

MANUFACTURING

SYMBOL

44AA

THIS FIGURE TO BE USED W1TH CALIBRATION

CHART FOR PINION DEPTH SETTING

F 1387-A

FIG. 24-po and Ring Gear

Markings

axle as a matched set never sep arately.

Be sure that the same matching number appears on both the drive pinion and the ring gear.

Note the number "666F" in Fig. 24.

4. Start the rear bearing on the drive pinion with its tapered end up, then press the bearing on the pinion

.

PRESS RAM

WOOD OR

FIBER BLOCK

/

FIG. 25-Pinion Rear Bearing

Installation

_-4621-A

4-14

shaft as shown in Fig. 25.

Use a 0.0015-inch feeler gauge between the bearing and the pinion gear to be sure that the bearing is fully seated.

5. After determining the correct shim thickness and installing the rear bearing as explained in the fore going steps, install the new pinion and ring gear as outlined under "As sembly."

DIFFERENTIAL CASE,

BEARINGS, AND RING GEAR

If the ring gear runout check be fore disassembly exceeded specifi cations, the condition may be caused by a warped ring gear, a defective case, or by excessively worn differ ential side bearings.

To determine the cause of exces sive runout proceed as follows:

1. Remove the ring gear from the case, and install the case back in the housing with side bearings and cups still installed.

2. Check the runout of the case flange with a dial indicator. If the runout does not now exceed speci fications, install a new ring gear to the case during assembly.

If the runout still exceeds specifications, the ring gear is true and the trouble is due to either a defective case or worn bearings. Continue with steps

3 through

5.

3.

Remove the differential case from the carrier housing and re move the side bearings from the case, using the tool shown in Fig. 21.

4. Press new bearings on the case hubs with tool 4222-H, and again install the differential case assembly in the housing without the ring gear.

5. Check the case runout again with the new bearings. If the runout is

now

within specifications, the old bearings were excessively worn. Use new bearings for assembly. If the runout is still excessive, the case is defective and should be replaced.

SPRING PLATE ASSEMBLED WITH

CONVEX SIDE TOWARD CASE

SIDE

GEAR RING

GROUP 4-REAR AXLE

ASSEMBLY

CONVENTIONAL

DIFFERENTIAL CASE

ASSEMBLY

1. Place a thrust washer over

each pinion and side gear. Assemble the pinion and side gears in the differential case and secure them with the pinion shaft Fig. 6, Part

4-1.

Lubricate all differential parts liberally with

axle

lubricant during assembly.

2. Slide the side gears and thrust washers tightly against the pinion gear. Then, using a feeler ribbon, check the clearance between the case and the thrust washers. If the clear ance exceeds 0.015

inch, new thrust washers must be installed.

3. Align the lock pin hole in the pin ion shaft with the bole in the case and install the lock pin. Peen the case metal over the lock pin.

4. Place the differential case as sembly in a holding fixture, tool

4205-B. Install the ring gear and secure it with bolts. Torque the bolts to specifications.

"DIRECTED POWER"

DIFFERENTIAL

CASE ASSEMBLY

1. Select the side gear ring and the clutch pack that pertains to the ring gear half of the differential case Fig. 26. Assemble to the side gear ring in order: a flat clutch plate with external lugs, a clutch disc with internal splines, a clutch plate, the spring disc with convex side toward the case, and the spring plate with convex side to ward the case.

2. Assemble the remaining clutch

070

FIG.

28-Assembly of Differential

Case Halves

plates and discs to the side gear that pertains to the cover half of the case.

Follow the same order of assembly as in the foregoing step.

3. Hold each differential case half on its side and install the pertinent side gear ring with plates and discs assembled.

Make sure that the clutch plate lugs are aligned and that they enter the slots in the case

Fig. 27. The side gear ring will

rotate with a slight drag when properly seated in the case.

4. With the ring gear half of the case in an upright position, as in

Fig.

28, place the proper side gear on the side gear ring. Place the lower ring gear half mate shaft and pinions on the side gear ring so that the locating marks on the

AXLE SHAFTS MUST

BE INSERTED ALL

THE WAY TO

ALIGN BOTH

CLUTCH

SPRING DISC

ASSEMBLED WITH

CONVEX SIDE TOWARD CASE E1393-A

FIG. 26-Positioning of Parts for

Assembly

FIG. 2l-Installation of Side Gear

Ring, Discs, and Plates in Case

El 396.A

FIG.

29-Spline Alignment of Side

Gear and Side Gear Ring

071 mate shaft are aligned with the cor responding marks on the case. Posi tion the upper cover half mate shaft and pinions with marks aligned, and set the cover half side gear on top of the four pinions Fig. 28.

5. While holding the side gear and clutch pack in the cover half of the case, install the cover half on the ring gear half so that the locating marks on each differential case half are in alignment Fig. 28.

6. Install the differential case bolts and turn them in a few threads.

7.

Align the splines of the side gears and side gear rings by insert ing the axle shaft on each side of the case. Be sure the shaft goes all the way in to engage both side gear and side gear ring splines Fig.

29.

8. With the axle shafts in posi tion, torque the differential case bolts evenly and alternately to speci fications.

9.

Remove the axle shafts and check for proper assembly.

If the differential has been properly as sembled, each mate shaft should be tight in its ramp; or, if there is clearance between the shaft and the ramp, the clearance should be equal at all four mate shaft ends.

INSTALLATION OF PINION,

BEARINGS, AND

DIFFERENTIAL CASE

1. Before installing the pinion and hearings, measure the differential ease side clearance as outlined in the following steps.

a Turn the axle housing as sembly in the fixture so that the

FIG. 3O-Measuring Differential

Case Side Clearance

PART 4-2-REAR AXLE

4-15

FIG.

3l-Pinion Rear Bearing

Cup Installation

front end is bearings tool ferential case down.

Place dummy

4205-C on the dif hubs, and install the case in the housing.

b Install the bearing caps in their correct position as indicated by the identification marks, and in stall the cap retaining bolts finger tight.

c Set up a dial indicator with its contact point against the back face of the ring gear as shown in

Fig.

30. Grasp both sides of the ring gear firmly as shown, and with a steady pressure move the en tire differential assembly in one di rection to the limit of its travel.

Adjust the indicator to zero.

d in the

same manner, move the differential assembly as far as it will go in the opposite direction.

Note the reading on the dial indi cator.

This reading indicates the amount of shims needed behind the differential side bearings to take up ihe total clearance between the hearing caps and the case.

Record this reading for use later

in

the assembly procedure.

e Remove

the differential case from the housing, and remove the dial indicator and dummy bearings.

2. Install the pinion locating shim pack, and then install the rear bear ing cup Fig.

3 I

.

If the original ring gear and pinion is being in stalled, use the original shim pack.

If a new gear set is being installed, use a corrected shim pack as ex plained under "Parts Replacement and Repair" in this section.

-TooI4616

E 1419-A

FIG. 32-Pinion Front Bearing

Cup Installation

3.

Turn the front end of the axle housing up, and install the front bearing cup Fig. 32.

4. The rear face of the pinion

gear either new or old should be lightly stoned to remove any ir regularities or burrs before at tempting a pinion gear depth reading.

Turn the housing to a horizontal

‘TooI-4858-B

E1398-A

FIG.

33-Drive Pinion and Bearing

Assembly Installation

4-16

GROUP 4-REAR AXLE

072 j

Torque

Indicator-4209

TooI-.-4858-B

FIG.

34-Measuring Pinion

Bearing Preload

position, and install the drive pinion and rear bearing assembly by in serting it from the rear side of the housing. Install the front bearing without preload shims and tool

4858-B on the pinion shaft, then turn the housing to an upright posi tion. Draw these parts together in the housing by turning the nut on the tool Fig. 33.

5. Tighten the nut on tool 4858-B until the torque required to rotate the drive pinion in the housing is

15 in-lbs as shown on the torque indicator Fig. 34.

6. To verify the selection of the pinion locating shim, measure the pinion depth as outlined in the fol lowing steps: a Check the micrometer accu racy of the pinion depth gauge tool

4020-B. The zero setting on the

FIG.

35-Pinion Depth Gauge

Adjustment

E1400-A

MICROMETER ASSEMBLY

FIG.

36-Measuring Pinion Depth

barrel should coincide with the 1inch mark on the thimble Fig. 35.

If the micrometer adjustment is out

0.003 inch or more, loosen the Allen screw and turn the barrel until the zero mark reaches the 1-inch mark on the thimble. When the adjustment is set, tighten the Allen screw. For errors smaller than 0.003 inch turn the barrel with the spanner wrench until the error is corrected.

b Remove the outer lock rings

from the gauge shaft Fig.

35.

Position the aligning bushings as shown in the insert in Fig. 36.

c Install the gauge shaft and micrometer assembly in the housing as shown in Fig. 36. Install the bearing caps and bolts. Torque the bolts to specifications. Attach the anvil clamp assembly to the differential housing. The anvil clamp should be

positioned, as shown, with the em bossed letters facing downward.

Place the anvil block on the pinion, as shown.

Tighten the clamping screw against the anvil block.

d

Refer to the calibration chart in Table 1 to determine the correct shim thickness for the pinion that is installed. Check the pinion mark ing Fig.

24.

The micrometer reading shown in the calibration chart under the pinion marking of the pinion being used indicates the correct shim thickness.

073

PART 4-2-REAR

AXLE

TABLE 1-Calibration Chart Gauge

4020-B

Marking

+10

+9

+8

+7 +6

*Micrometer

.865

.866

.867

.868

Pinion

*Allowable Tolerance: 0.001 inch.

.869

+5 +4

.870

.871

+3 -F2 +1

.872

.873

.874

0 -1 -2 -3 4

.875

.876

.877

.878

.879

e Turn the micrometer thimble until the spindle just contacts the anvil of the gauge tool, and take the micrometer readings. Figs. 35 arid 36. If the micrometer reading varies more than 0.001 inch from the specifications in the calibration chart, the pinion shim pack will re quire an adjustment. If the microm eter reading obtained is greater than that specified in the chart, it will be necessary to remove 0.001 inch in shim stock for each 0.001 inch dif ference between the micrometer reading and that specified in the chart.

Conversely, if the micrometer reading is less than that specified in the chart, it will require the installa tion of 0.00 1 inch in shim stock for each 0.001 inch difference between the micrometer reading and that specified in the chart.

7. Remove the gauge tool. If the micrometer reading was within speci fications, proceed with step 9. if shim adjustment is required, remove the pinion and rear hearing assem bly

Fig.

18.

Then remove the pinion rear bearing cup. Fig. 19.

When adding or removing shims, measure each shim separately.

Check the bearing bore for burrs or upset metal. If any is present, it must be removed. Make sure that the bearing cup and shim pack are fully seated in the bore.

Install the pinion rear hearing

FIG.

31-Establishing Pinion

Bearing Preload

cup Fig. 31, then install the pinion and bearing assembly in the housing

Fig. 33.

8. If shims were installed or re moved, recheck the pinion depth as outlined in step 6.

9. Establish the pinion bearing preload as outlined in the following steps.

a With the drive pinion set at its correct depth, remove the pinion and the pinion front bearing Fig.

18.

b Install the drive pinion again, and place the bearing preload shims over the forward end of the pinion shaft. If the pinion location shim pack behind the rear bearing

Cup was not changed, install the original preload shim pack.

if the pinion location shim pack was changed, add or subtract the same number of shims from the preload pack as was added or subtracted from the pinion location pack.

c Start the front bearing over the shaft with its tapered end down.

Press the bearing on the shaft with the tool shown in Fig. 33. Using tool 4858-G, torque the nut on the tool to 200-220 ft-lbs Fig. 37.

d With the pinion shaft in a vertical position, and using tool

4209 as shown in Fig. 34 check the torque required to rotate the drive pinion. Correct preload will be obtained when the torque re quired to rotate the pinion is as specified in Part 4-3.

e If the torque is less than the minimum specified, remove the front pinion bearing and remove, shims.

If the torque exceeds the maximum specified, install shims. Install the front bearing again, and recheck the preload.

10. Place the oil slinger over the drive pinion and against the bearing with its concave side up Part 4-1,

Fig. 6.

11. Install the oil slinger gasket.

12. Start the new seal over the drive pinion with the sealing edge pointing down; then, using the tool shown in Fig.

10, drive the seal into position.

13. Start a new seal deflector over the companion flange and drive the deflector into position on the

1

*TooI4859

Tool- 4858-B

I

I

FIG. 39-U-Joint

Flange

Installation-On Bench

DUST DEFLECTOR

COMPANION FLANGE

4-17

E1404-A

FIG. 38-U-Joint

Flange

Deflector Installation

flange Fig.

38.

Start the com panion flange over the drive pinion and press the flange into position as shown in Fig. 39.

14. Install the washer and lock nut on the pinion shaft. While hold ing the flange with the tool shown in Fig. 17, torque the nut to speci fications.

15. Refer back to the reading re corded in step 1. This reading taken before the pinion was installed rep resents the total clearance between the differential side bearing cups and the case. Perform the following steps for determining the number of shims required at each bearing to take up

4-18

GROUP 4-REAR AXLE

FIG. 40-Differential Bearing Preload and Ring Gear Backlash Adjustment

the clearance and establish preload and backlash: a

Place the dummy bearings tool 4205-C on the differential hubs, and again install the differ ential assembly in the housing this time with the pinion installed. In stall the bearing caps in their proper positions. Install and tighten the re taining bolts finger tight. Install the dial indicator with the contact point against the back face of the ring gear as shown in Fig. 30. Move the differential and ring gear as sembly tight against the pinion gear, and then set the dial indicator to zero. Move the differential and ring gear assembly away from the pinion as far as possible, and note the reading.

b This reading indicates the amount of shims necessary to take up the clearance between the bear ing cup and the case at the ring gear side of the differential as sembly. Subtract this reading from the previously recorded total read ing to obtain the amount of shims necessary to take up the clearance between the bearing cup and the case at the pinion side of the dif ferential. Increase this pinion side shim pack by an additional 0.015

inch in order to provide correct bear ing preload and backlash.

EXAMPLE Fig. 40:

Total Clearance previously recorded

.

.0.070 inch

Less reading in foregoing step a

Amount of shims necessary to take up clearance at ring gear side

Shims necessary to take up clearance at

0.038 inch pinion side

0.032 inch

Plus 0.015 inch shims for preload and backlash. .0.015 inch

Total amount of

shims

at pinion side 0.047 inch

074

16. Remove the dial indicator, bearing caps and differential case from the housing.

Remove the dummy bearings from the differ ential case.

17. Install the required number of shims on the bearing case. Using tool 4222-H, press the side bearings

on

the

case.

18. Attach the spreader tool to the housing, as shown in

Fig.

16, making certain the dowels on the tool enter the openings in the housing. Spread the housing enough to permit installation of the differential case and bearing as sembly. Do not spread the housing more than 0.020 inch.

19. Install the bearing, caps in their respective positions as indi cated by the markings on the caps and housing Fig. 15. Remove the spreader. Place some sealing com pound on the bearing cap bolts.

Install and torque the bolts to specifications.

20. With the dial indicator at tached to the housing, as shown in

Fig. 4, Part 4-1, check the backlash between the ring gear and pinion at four equally spaced points around the ring gear.

The backlash should not be less than 0.003 inch or exceed 0.008

inch, and must not vary more than

0.002

inch between the positions checked.

21. Attach a dial indicator to the

differential housing as shown in

Fig.

5,

Part

4-1. With the indicator set at "zero", revolve the ring gear at least one revolution and check the total ring gear runout. The total indicator reading, or runout, should not exceed 0.006 inch.

22. Make a final tooth contact

pattern check.

23. Install the gasket and differ ential cover with the gear identifi cation taB beneath one of the cover bolts. Torque the bolts to specifi cations.

24. Refill the axle with specified

lubricant.

[

0Th

P1T

SPECIFICATIONS

REAR AXLE

ADJUSTMENTS

Description

Backlash Between Ring Gear and Pinion

Maximum Backlash Variation Between Teeth

Maximum Runout of Backface of

Ring Gear as Assembled

Nominal Pinion Locating Shim

Available Pinion Locating Shims Inches

Available Pinion Bearing

Preload Shims

Maximum Carrier Housing Spread

Inches

0.003-0.008

0.002

-

0.006

0,030

0.0025, 0.0035,

0.0045, 0.0055, 0.009,

0.011, 0.027, and 0.033

0.003, 0.005,

0.010 and 0.030

0.020

PINION AND DRIVE GEAR IDENTIFICATION

LUBRICANT

Capacity 4.8 Pints

4-19

TORQUE LIMITS Ft-Ibs

Differential Bearing Cap Retaining Bolts

Ring Gear to Differential Case

"Directed Power" Differential Case Half Retaining Bolts

Carrier Rear Cover Retaining Bolts

Bumper Bracket to Carrier Housing Retaining Bolts

U-Joint Flange to Drive Pinion Shaft Nut

Drive Shaft to Axle U-Joint Flange Bearing Cap Bolts

Minimum Pinion Nut Torque

Required to Obtain Correct Pinion Bearing Preload

Rear Spring U-Bolt Nuts

Rear Wheel Bearing Retainer Plate to Axle Housing

Rear Shock Absorber to Axle Mounting Stud Nuts

PINION BEARING PRELOAD ADJUSTMENT

lescription

With Seal New Bearings

Inch

Pounds

22-24

With Seal Old Bearings

Without Seal New Bearings

Without Seal Old Bearings

12-16

18-20

8-12

70-90

50-60

35-45

15-25

20-30

200-220

15-20

200-220

50-60

50-65

30-40

DRIVE PINION ADJUSTING SHIM THICKNESS CHANGES Inches

Pinion

0

+0.008

+0.007

+0.006

+0.005

+0.004

+0,003

+0.002

+0.001

0

3

+0.007

+0.006

+0.005

+0.004

+0,003

+0.002

+0.001

-,.---,4

0

-0.001

.___________

-2

+0.006

+0.005

+0.004

-

+0.003

-

+0.002

+0.001

-

0

-0.001

-0.002

-1

+0.005

+0.004

+0.003

+0.002

-

+0.001

0

-0.001

-0.002

-0.003

+0.004

+0.003

+0.002

+0.001

0

-0.001

-1.002

-0.003

-0.004

New Pinion Marking

-___________

-

+1

+0.003

+0,002

+0.001

0

-0.001

-0.002

-0.003

---,-

-0.004

-0.005

+2

+0.002

+0.001

0

-0.001

-0.002

-0.003

-0.004

-0.005

-0.006

+3

+0.001

0

-0.001

-0.002

-0.003

-0.004

-0.005

-0.006

-0.007

+4

0

-0.001

-0.002

-0.003

-0.004

-0.005

--

-0.006

-0.007

-0.008

cc=

0

"4