Group 22 Service procedures - intake and exhaust systems
Turbocharger, reconditioning
Schwitzer S4T (TAD1630, TAD1631)
8.
9.
10.
11.
12.
1.
2.
3.
4.
5.
6.
7.
Compressor Wheel
Lock nut
Compressor Cover
Piston ring holder
Shim (optional)
Piston ring
Cover
Screws
Thrust bearing
V-clamp
Thrust washers
Spacer sleeve
20.
21.
22.
23.
13.
14.
15.
16.
17.
18.
19.
Bearing housing (complete)
V-clamp
Circlips
Heat Shield
Piston ring
Turbine housing
Shaft and wheel (complete)
Snap ring
O-Ring
Bearings
Oil deflector
Disassembly
1
Mark the relative positions of the compressor cover (3) and turbine housing (19) to the bearing housing (13).
2
Fix the turbine housing in the vise using soft jaws. The turbocharger shaft should be vertical.
3
Remove the V-clamp (10) securing the compressor cover.
4
Remove the compressor cover (3).
5
Remove the V-clamp securing the turbine housing.
6
Lift the central bearing housing out of the turbine housing.
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Service procedures - intake and exhaust systems
7
Clamp a suitable 12 point socket wrench in the vise with the socket axis vertical.
8
Group 22
10
Gently remove the turbine shaft and wheel by tap- ping with a small soft faced mallet on the compressor end of the shaft.
Be careful not to bend or damage the shaft.
11
Place the bearing housing (13) on the turbine backplate (16)
(if fitted) on the bench and remove the insert retaining snap ring (20).
12
Carefully bend up the cover (7) using two screwdrivers.
Note: Thread a piece of plastic tubing over the screwdrivers to avoid damaging the bearing housing.
13
Dismantle the insert assembly by pushing the piston ring holder (4) out of the insert.
14
Remove the 2 screws retaining the oil deflector (23). This will allow the oil deflector, thrust bearing (9), thrust washers (11) and spacer sleeve (12) to be removed from the bearing housing.
15
Using suitable circlip pliers, remove the outer circlips from both ends of the bearing housing, remove the journal bearings and inner circlips.
Place the 12 point hub of the turbine wheel into the socket.
Release the compressor wheel locknut (2).
Note: Use a T-handle wrench together with a universal joint to avoid side-loading the turbine wheel shaft.
9
Remove the compressor nut and slide the compressor wheel from the turbine shaft. Some models have shims (5) fitted between compressor wheel and piston ring holder (4).
The position and thickness of any shims should be noted.
Note: If the compressor wheel is sticking it may be heated with a hot air pistol to a max of 130°C (266°F).
Cleaning of Parts
1 Aluminum parts
Soak in a non-caustic solvent until all deposits have been softened. Clean surfaces with bristle brush and soft scraper.
Steam may be used providing bearing surfaces are protected.
2 Cast iron parts
Soak in non-caustic solvent.
Alternatively blast. Be careful with internal profile surfaces.
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Group 22 Service procedures - intake and exhaust systems
3 Shaft and wheel assembly
Soak in solvent to remove oily residue. Mask entire shaft section and totally clean wheel and hub using steam. Avoid concentrating on piston ring seal groove.
6 Turbine heat shield (16)
Replace if cracked or warped.
Inspection of parts
7 Piston ring holder (4)
Check piston ring groove width max 1.58 mm (0.0623") and for signs of taper or damage to groove. Reject if worn.
1 Bearing Housing
Inspect bearing bore visually for sign of damage or wear.
Check turbine end seal bore for damage.
2 Compressor Wheel (1)
Visually inspect for evidence of bent, burred, nicked or eroded blades, and for evidence of scuffing on the back face.
Very minor damage is acceptable. Reject and replace if damage appears sufficient to affect wheel balance. Do not attempt to straighten any bent blades.
3 Shaft and wheel assembly
Check journal diameter for wear. Minimum diameter is 15.99
mm (0.6300") or 17.43 mm (0.6867") (actual size depends on model).
Check seal groove width max 1.58 mm (0.0623").
Measure eccentricity between large and small shaft diameter, max 0.008 mm. T.I.R.(0.0003").
Check balance to 0.36 gm mm (0.0005 oz. inch) in both planes. Replace if outside limits.
4 Compressor cover (3)
Visually inspect for evidence of contour damage. Replace if damage is excessive.
5 Turbine housing (18)
Visually inspect for damage and excess temperature damage such as cracking, pitting, warping, erosion. Reject and replace if damage is excessive.
8 Thrust washer (11)
Replace if thrust surfaces are worn. In most cases these may be reused by reversing the position so that the non worn side is in contact with the thrust bearing.
9 Spacer sleeve
This part should show no sign of surface damage or wear.
Assembly
1
Use only the parts complying with the dimensions outlined in the inspection instructions above plus an ”Overhaul Kit”.
2
All parts must be washed in clean solvent and dried with compressed air.
3
Fit the inner snap rings to the bearing housing bushing. Add a few drops of oil to the bushing and fit the journal bearings and outer snap rings.
4
Fit a new piston ring to the groove in the shaft and wheel assembly.
5
Fit turbine backplate (16) over the shaft section so that it rests on the back of the turbine wheel.
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Service procedures - intake and exhaust systems
6
Fit the shaft and wheel etc. into the bearing housing after lubricating both shaft and piston ring. Take care not to damage the piston ring when inserting the sealing bore.
7
Place this assembly in the turbine housing with the shaft vertical.
8
Fit the thrust washer (11) and spacer (12) onto the shaft.
Group 22
15
Fit the compressor wheel (1) and lock nut (2). On models that have shims (5) under the compressor wheel, ensure that all shims are refitted (if a new compressor wheel or compressor cover are to be used, adjust the shims as required to achieve a minimum clearance between compressor wheel and cover of 0.23 mm (0.09").
16
Clamp the appropriate 12 point socket wrench in the vise with the socket axis vertical.
17
9
Fit the thrust bearing (9) into the bearing housing (13) and lubricate the bearing surfaces.
10
Fit the second thrust washer and oil deflector. Fit the two retaining screws and torque to 5.0-5.7 Nm (45-50 in-lb).
11
Fit a new O- ring (21) to the groove in the bearing housing.
12
Fit a new piston ring (6) into the piston ring holder (4).
13
Assemble the piston ring holder assembly into the insert taking care not to damage the piston ring.
14
Lubricate the O- ring (21) and mount the insert into the bearing housing and retain with the snap ring. Ensure that the bevelled edge is turned upward.
Place the 12 points hub of the turbine wheel into the socket.
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Group 22
18
Service procedures - intake and exhaust systems
Torque the compressor lock nut with a T-handle torque wrench to 13.6 Nm (10 ft-lb) and then rotate to an additional
90°-95° and apply 2 drops of Loctite 601 to the threads.
Note: Use a T-handle torque wrench together with a universal joint to avoid side-loading the turbine wheel shaft.
19
Fit the bearing assembly into the compressor cover (3), align with the marks, fit the V-clamp (10) and torque the locknut to
11 Nm (8 ft-lb).
20
Fit the bearing assembly into the turbine housing, align with the marks, fit the V-clamp and torque the locknut to 11 Nm
(8 ft-lb).
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