Differential System (Except Sti): Diagnosis Subaru Impreza GH

INSPECTION

1. Remove the filler plug, and then check the gear oil. Replace the gear oil if it is contaminated or deteriorated. Ref. to «REPLACEMENT»(ref-357279-S38327633232010031100000) .
2. Check that the gear oil level is within -5 mm (-0.2 in) from the bottom of the filler plug hole. If the level is low, make sure that there is no oil leakage and refill up to the bottom of filler plug.

Scheme 100

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Scheme 102

1. Lift up the vehicle.
2. Remove the oil drain plug and filler plug, and drain the gear oil. CAUTION: Gear oil is extremely hot just after driving. Be wary of receiving burns.
3. Tighten the oil drain plug. NOTE: Apply liquid gasket to the drain plug. Liquid gasket: THREE BOND 1105 (Part No. 004403010) or equivalent Tightening torque: 49 N.m (5.0 kgf-m, 36.1 ft-lb)
4. Fill the differential carrier with gear oil to the bottom of filler plug. NOTE: Carefully refill oil while watching the level. Excessive or insufficient oil must be avoided. Recommended gear oil: Ref. to «SPECIFICATION»(ref-357279-S34496348252010031100000) , General Description. Oil capacity: 0.8 l (0.8 US qt, 0.7 lmp qt)
5. Install the filler plug.

Note. Apply liquid gasket to the filler plug.

Liquid gasket

THREE BOND 1105 (Part No. 004403010) or equivalent

Tightening torque

49 N.m (5.0 kgf-m, 36.1 ft-lb)

Wash all the disassembled parts clean, and examine them for wear, damage and other defects. Repair or replace the defective parts as necessary.

1. Hypoid driven gear and drive pinion If there is evidently an abnormal tooth contact, find out the cause and adjust until the teeth contact correctly. Replace the gear if there is an excessive worn or an incapable adjustment. If crack, cutout or seizure is found, replace the parts as a set. Slight damage of some teeth can be corrected by oil stone or the like.
2. Side gear and pinion mate gear Replace if cracks, scoring or other defects are evident on the tooth surface. Replace if thrust washer contact surface is worn or seized. Slight damages of the surface can be corrected by oil stones or equivalent.
3. Bearing Replace if seizure, peeling, wear, rust, dragging during rotation, abnormal noise or other defect is evident.
4. Thrust washer of the side gear and pinion mate gear: Replace if seized, flawed, abnormally worn or having other defects.
5. Oil seal Replace if deformed or damaged, and at every disassembling.
6. Differential carrier Replace if the bearing bores are worn or damaged.
7. Differential case Replace if its sliding surfaces are abnormally worn, burned, or cracked.
8. Companion flange

Replace if the oil seal lip contact surface shows cracking.

Check that there is no leakage from front oil seal portion. If there is any leakage replace the oil seal and inspect the propeller shaft.

Scheme 103

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Scheme 108

1. Disconnect the ground cable from battery.
2. Shift the select lever or gear shift lever to neutral.
3. Release the parking brake.
4. Lift up the vehicle.
5. Remove the oil drain plug, and drain gear oil.
6. Install the oil drain plug. NOTE: Apply liquid gasket to the drain plug. Liquid gasket: THREE BOND 1105 (Part No. 004403010) or equivalent Tightening torque: 49 N.m (5.0 kgf-m, 36.1 ft-lb)
7. Remove the rear exhaust pipe and muffler. Non-turbo model Ref. to «REMOVAL»(ref-357254-S32999093642010031100000) , Rear Exhaust Pipe. Ref. to «REMOVAL»(ref-357254-S17169301122010031100000) , Muffler. Turbo model Ref. to «REMOVAL»(ref-357260-S02665767832010031100000) , Rear Exhaust Pipe. Ref. to «REMOVAL»(ref-357260-S20286020412010031100000) , Muffler.
8. Remove the heat shield cover.
9. Remove the propeller shaft. Ref. to «REMOVAL»(ref-357249-S12597038342010031100000) , Propeller Shaft.
10. Remove the self-locking nut while holding the companion flange with ST. ST 498427200 FLANGE WRENCH
11. Extract the companion flange using ST. ST 399703600 PULLER ASSY
12. Remove the oil seal using ST or screwdriver. ST 398527700 PULLER ASSY
13. Install a new oil seal using ST. ST 498447120 INSTALLER
14. Install the companion flange. NOTE: Use a plastic hammer to install companion flange.
15. Tighten the self-locking nut to the specified torque so that the rotating resistance of the companion flange is the same value as that before replacing the oil seal. ST 498427200 FLANGE WRENCH NOTE: Use a new self-locking nut. Before installing the self-locking nut, apply seal material to self-locking nut threads. Seal material: THREE BOND 1324 (Part No. 004403042) or equivalent Tightening torque: 181.5 N.m (18.5 kgf-m, 133.9 ft-lb)
16. Hereafter, reassemble in the reverse order of disassembly.
17. After installing, fill the differential carrier with gear oil up to the bottom of the filler plug hole. Ref. to «REPLACEMENT»(ref-357279-S38327633232010031100000) .

Check that there is no oil leakage from the side oil seal. If there is any leakage, replace the oil seal.

Scheme 109

1. Remove the rear differential. Ref. to «Rear Differential»(ref-357279-S34207498522010031100000) .
2. Remove the rear differential side oil seal using ST. ST 398527700 PULLER ASSY
3. Using the ST, install the oil seal to the side retainer. NOTE: Apply differential gear oil to the oil seal lips. ST 398437700 DRIFT
4. Install the rear differential. Ref. to «INSTALLATION»(ref-357279-S34988301082010031100000) , Rear Differential.

1. Check the rear differential front member for damage, bend and corrosion. If damage, bend or corrosion is excessive, replace the rear differential front member.
2. Check the bushings of rear differential member for cracking, hardening and damage.

If cracking, hardening or damage is excessive, replace rear differential front member.

PROBLEM SYMPTOM REFERENCE CHART