Home ReviewsRefund
Home/Subaru/Impreza/Subaru Impreza GH (2007-2011)/Repair manual/Differentials & Drive Axles/Differential (Sti): Other
Contents Wiring diagrams Section: Differentials & Drive Axles All sections

Differential (Sti): Other Subaru Impreza GH

Differentials & Drive Axles 30 illustrations ~1402 words

REAR DIFFERENTIAL

When replacing a rear differential assembly, select the correct one according to the following table.

Note. Using a different rear differential assembly will cause the drive train and tires to drag or emit abnormal noise.

Model2.5 L Turbo STI
6MT
Rear differential typeT-type
IdentificationH3
LSD typeTorsen
Type of gearHypoid gear
Gear ratio (Number of gear teeth)3.545(39/11)
Oil capacity1.0 l (1.1 US qt, 0.9 lmp qt)
Rear differential gear oilGL-5

MODEL SPECIFICATIONS

REAR DIFFERENTIAL GEAR OIL

Recommended gear oil

GL-5 (75W-90)

CAUTIONEach oil manufacturer has its base oil and additives. Thus, do not mix two or more brands.

Scheme 69

Scheme 69
Scheme 69

SERVICE DATA

Drive pinion bearing preload (For new bearing)Measure with spring measurement. (Measured from the companion flange bolt) N (kgf, lbf)24.1 - 38.6 (2.5 - 3.9,5.4 - 8.7)
Measure with torque wrench N.m (kgf-m, ft-lb)0.98 - 1.57 (0.10 - 0.16,0.72 - 1.16)
Side bearing standard widthMm (in)20.00 (0.7874)
Hypoid driven gear to drive pinion backlashMm (in)0.10 - 0.20 (0.004 - 0.008)
Hypoid driven gear runout on its back surfaceMm (in)0.05 (0.002)

SERVICE DATA

ADJUSTING PARTS

Preload adjusting spacerPart No.Length mm (in)
31454AA13052.2 (2.055)
31454AA14052.4 (2.063)
31454AA15052.6(2.071)
31454AA16052.8 (2.079)
31454AA17053.0 (2.087)
31454AA18053.2 (2.094)

PRELOAD ADJUSTING SPACER SPECIFICATIONS

Preload adjusting washerPart No.Thickness mm (in)
3837052002.59(0.1020)
3837152002.57(0.1012)
3837252002.55(0.1004)
3837352002.53 (0.0996)
3837452002.51 (0.0988)
3837552002.49 (0.0980)
3837652002.47 (0.0972)
3837752002.45 (0.0965)
3837852002.43 (0.0957)
3837952002.41 (0.0949)
3838052002.39(0.0941)
3838152002.37 (0.0933)
3838252002.35 (0.0925)
3838352002.33(0.0917)
3838452002.31 (0.0909)
Pinion height adjusting washer38336AA2303.09(0.1217)
38336AA2403.12 (0.1228)
38336AA2503.15 (0.1240)
38336AA2603.18(0.1252)
38336AA2703.21 (0.1264)
38336AA2803.24(0.1276)
38336AA2903.27(0.1287)
38336AA3003.30 (0.1299)
38336AA3103.33(0.1311)
38336AA3203.36 (0.1323)
38336AA3303.39 (0.1335)
38336AA3403.42 (0.1346)
38336AA3503.45 (0.1358)
38336AA3603.48 (0.1370)
38336AA3703.51 (0.1382)
38336AA3803.54 (0.1394)
38336AA3903.57 (0.1406)
38336AA4003.60(0.1417)
38336AA4103.63(0.1429)
38336AA4203.66(0.1441)
Side retainer shim3834752010.20 (0.0079)
3834752020.25 (0.0098)
3834752030.30(0.0118)
3834752040.40 (0.0157)
3834752050.50(0.0197)

PRELOAD ADJUSTING WASHER SPECIFICATIONS

Scheme 70

Scheme 70: REAR DIFFERENTIAL WITH LSD (T-TYPE)
Scheme 70: REAR DIFFERENTIAL WITH LSD (T-TYPE)

Tightening torque: N.m (kgf-m, ft-lb)

T1: 10.5 (1.1, 7.7)

T2: 44 (4.5, 32.5)

T3: 60 (6.1, 44.3)

T4: 103 (10.5, 76.0)

T5: 181.5 (18.5, 133.9)

Scheme 71

Scheme 71: REAR DIFFERENTIAL MOUNTING SYSTEM
Scheme 71: REAR DIFFERENTIAL MOUNTING SYSTEM

Tightening torque: N.m (kgf-m, ft-lb)

T1: 50(5.1, 36.9)

T2: 70 (7.1, 51.6)

T3: 110 (11.2, 81.1)

CAUTION

  1. Wear appropriate work clothing, including a cap, protective goggles and protective shoes when performing any work.
  2. Remove contamination including dirt and corrosion before removal, installation or disassembly.
  3. Keep the disassembled parts in order and protect them from dust and dirt.
  4. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly and replacement.
  5. Vehicle components are extremely hot after driving. Be wary of receiving burns from heated parts.
  6. Use SUBARU genuine gear oil, grease. Do not mix gear oil, grease, etc. of different grades or manufacturers.
  7. Be sure to tighten fasteners including bolts and nuts to the specified torque.
  8. Place shop jacks or rigid racks at the specified points.
  9. Apply gear oil onto sliding or revolving surfaces before installation.
  10. Before installing the O-ring or snap ring, apply a sufficient amount of gear oil to avoid damage and deformation.
  11. Before securing a part on a vise, place cushioning material such as wood blocks, aluminum plate, or cloth between the part and the vise.
  12. Avoid damaging the mating surface of the case.

GENERAL TOOL

TOOL NAMEREMARKS
Transmission jackUsed for removing and installing the rear differential.
PullerUsed for removing the side retainer.
Thickness gaugeUsed for measuring clearance.

GENERAL TOOL CHART

Scheme 72

Scheme 72: INSPECTION
Scheme 72: INSPECTION

Scheme 73

Scheme 73
Scheme 73
  1. Disconnect the ground cable from battery.
  2. Disconnect the oil temperature switch connector.
  3. Remove the oil temperature switch and check the gear oil. Replace the gear oil if it is contaminated or deteriorated. Refer to «REPLACEMENT»(ref-357107-S00235971132010030800000) , Differential Gear Oil.
  4. Check that the gear oil level is up to the bottom of the oil temperature switch hole. If the level is low, make sure that there is no leakage, and refill up to the bottom of the oil temperature switch hole.

Scheme 74

Scheme 74: REPLACEMENT
Scheme 74: REPLACEMENT

Scheme 75

Scheme 75
Scheme 75

Scheme 76

Scheme 76
Scheme 76

Scheme 77

Scheme 77
Scheme 77
  1. Disconnect the ground cable from battery.
  2. Lift up the vehicle.
  3. Disconnect the oil temperature switch connector.
  4. Remove the oil drain plug and oil temperature switch, and drain the gear oil. CAUTION: Gear oil is extremely hot just after driving. Be wary of receiving burns. Be careful not to spill the differential gear oil on exhaust pipe. If gear oil is spilled, wipe it off completely.
  5. Tighten the oil drain plug. NOTE: Use a new gasket. Tightening torque: 60 N.m (6.1 kgf-m, 44.3 ft-lb)
  6. Fill the differential carrier with gear oil to the bottom of oil temperature switch hole. NOTE: Carefully refill oil while watching the level. Excessive or insufficient oil must be avoided. Recommended gear oil: Refer to «SPECIFICATION»(ref-357107-S39220622472010030800000) , General Description. Oil capacity: 1.0 l (1.1 US at, 0.9 lmp qt)
  7. Install the oil temperature switch. NOTE: Use a new gasket. Tightening torque: 60 N.m (6.1 kgf-m, 44.3 ft-lb)
  8. Connect the oil temperature switch connector.
  9. Lower the vehicle.
  10. Connect the ground cable to battery.

NOTE

For the front differential of the manual transmission, refer to FRONT DIFFERENTIAL ASSEMBLY .

Scheme 78

Scheme 78: REMOVAL
Scheme 78: REMOVAL

Scheme 79

Scheme 79
Scheme 79

Scheme 80

Scheme 80
Scheme 80

Scheme 81

Scheme 81
Scheme 81

Scheme 82

Scheme 82
Scheme 82

Scheme 83

Scheme 83
Scheme 83

Scheme 84

Scheme 84
Scheme 84

Scheme 85

Scheme 85
Scheme 85

Scheme 86

Scheme 86
Scheme 86

Scheme 87

Scheme 87
Scheme 87

Scheme 88

Scheme 88
Scheme 88

Scheme 89

Scheme 89
Scheme 89

Scheme 90

Scheme 90
Scheme 90

Scheme 91

Scheme 91
Scheme 91
  1. Set the vehicle on a lift.
  2. Disconnect the ground cable from battery.
  3. Place the gear shift lever in neutral.
  4. Release the parking brake.
  5. Loosen the wheel nuts.
  6. Lift up the vehicle.
  7. Remove the wheels.
  8. Disconnect the oil temperature switch connector and ground connector.
  9. Drain the differential gear oil. Refer to «REPLACEMENT»(ref-357107-S00235971132010030800000) , Differential Gear Oil.
  10. Remove the rear exhaust pipe and muffler. Refer to «REMOVAL»(ref-357090-S25330699942010030800000) , Rear Exhaust Pipe. Refer to «REMOVAL»(ref-357090-S08053303402010030800000) , Muffler.
  11. Remove the heat shield cover.
  12. Remove the propeller shaft. Refer to «REMOVAL»(ref-357086-S03061160722010030800000) , Propeller Shaft.
  13. Remove the DOJ of rear drive shaft from rear differential. Remove the ABS wheel speed sensor cable from the clamp. Remove the bolts which secure the rear stabilizer link to the rear lateral link. Remove the bolts which secure the shock absorber to the rear lateral link. Remove the bolts which secure the rear lateral link to the housing. Remove the bolts which secure the trailing link to the housing. Remove the DOJ from the rear differential by using ST. NOTE: When removing the DOJ from the rear differential, fit the ST to the bolts as shown in the figure so as not to damage the side retainer. ST 28099PA100 DRIVE SHAFT REMOVER
  14. Suspend the rear drive shaft to the rear cross-member using wire.
  15. Remove the rear differential front member.
  16. Support the rear differential with the transmission jack.
  17. Remove the self-lock nuts which hold the rear differential to the rear crossmember.
  18. While slowly lowering the transmission jack, move the rear differential forward, and remove the rear differential from the vehicle.
  19. Remove the rear differential member plate from the rear differential.

Scheme 92

Scheme 92: INSTALLATION
Scheme 92: INSTALLATION

Scheme 93

Scheme 93
Scheme 93

Scheme 94

Scheme 94
Scheme 94

Scheme 95

Scheme 95
Scheme 95

Scheme 96

Scheme 96
Scheme 96
  1. Attach the rear differential member plate to the rear differential.
  2. Set the rear differential to transmission jack.
  3. Adjust the transmission jack and properly insert the rear differential stud bolt into rear crossmember bushing.
  4. After inserting the rear differential stud bolt into the rear crossmember bushing, lift up the transmission jack and align the rear differential to its attachment position.
  5. Tighten a new self-locking nut temporarily to rear crossmember.
  6. Install the rear differential front member with a new self-locking nut. Tightening torque: T1:50 N.m (5.1 kgf-m, 36.9 ft-lb) T2:110 N.m (11.2 kgf-m, 81.1 ft-lb)
  7. Tighten the self-locking nut. Tightening torque: 70 N.m (7.1 kgf-m, 51.6 ft-lb)
  8. Attach the ST to rear differential. ST 28099PA090 OIL SEAL PROTECTOR
  9. Insert the spline shaft until the spline portion comes inside the side oil seal.
  10. Remove ST from rear differential.
  11. Push the housing to fully insert the DOJ into the rear differential.
  12. Lower the transmission jack.
  13. Installing procedure hereafter is in the reverse order of removal.
  14. After installing, fill the differential carrier with gear oil up to the bottom of the oil temperature switch hole. Refer to «DIFFERENTIAL GEAR OIL»(ref-357107-S08759838792010030800000) .
  15. Inspect the wheel alignment and adjust if necessary.

HYPOID DRIVEN GEAR BACKLASH

Using a dial gauge, check the backlash of hypoid driven gear.

Hypoid driven gear backlash

0.10 - 0.20 mm (0.004 - 0.008 in)

If the hypoid driven gear backlash is not within the specification, adjust the side bearing preload or repair if necessary.

HYPOID DRIVEN GEAR RUNOUT ON THE BACK SURFACE

Using a dial gauge, check the hypoid driven gear back surface runout.

Hypoid driven gear back surface runout: 0.05 mm (0.002 in)

If the hypoid driven gear runout exceeds 0.05 mm (0.002 in), replace the hypoid driven gear.

TOOTH CONTACT BETWEEN HYPOID DRIVEN GEAR AND DRIVE PINION

Inspect the tooth contact between the hypoid driven gear and drive pinion. Refer to ASSEMBLY , Rear Differential (T-type).

TOTAL PRELOAD

Using a spring scale, check the total preload.

Total preload

27.0 - 54.0 N (2.8 - 5.5 kgf, 6.1 - 12.1 lbf)

If the total preload is not within the specifications, adjust the side retainer shims.

Scheme 97

Scheme 97: COMPANION FLANGE
Scheme 97: COMPANION FLANGE

Scheme 98

Scheme 98
Scheme 98
  1. If rust or dirt is attached to the companion flange, remove them.
  2. Set a dial gauge at a companion flange surface (mating surface of propeller shaft and companion flange), and then measure the companion flange runout. Limit of runout: 0.08 mm (0.003 in)
  3. Set the gauge inside of the companion flange, and measure the runout. Limit of runout: 0.08 mm (0.003 in)
  4. If either runout exceeds the limit, move the phase of companion flange and drive pinion 90° each, and find the point where the runout is within the limit.
  5. If the runout exceeds the limit after changing the phase, replace the companion flange and recheck the runout.
  6. If the runout exceeds the limit after replacing the companion flange, the drive pinion may be assembled incorrectly or bearing is faulty.

Adjust hypoid driven gear backlash. Refer to ASSEMBLY , Rear Differential (T-type).

Adjust the tooth contact between hypoid driven gear and drive pinion gear. Refer to ASSEMBLY , Rear Differential (T-type).

Adjust the side retainer shim. Refer to ASSEMBLY , Rear Differential (T-type).

More articles — Differential (Sti)