Rear Differential: Assembly

WARNING: This page is about a different car, the 2005 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Assemble in the reverse order of disassembly.
Check and adjust each part during assembly.
Keep the shims and washers in order, so that they are not improperly installed.
Thoroughly clean the surfaces on which the shims, washers and bearings are to be installed.
Apply gear oil to the bearings and thrust washers when installing them.
Be careful not to mix up the bearing races RH and LH.
Use new O-rings and gasket.
Replace the oil seals with new ones at every disassembly. Apply grease to the lips when installing the oil seals.
Be careful not to mix up the differential oil seal RH and LH.

Fig 1: Applying Grease To Lips When Installing Oil Seals
Courtesy of SUBARU OF AMERICA, INC.

Adjusting preload for front and rear bearings: Adjust the bearing preload with collar and washer between front and rear bearings. Pinion height adjusting washer are not affected by this adjustment. The adjustment must be carried out without oil seal inserted.

Press the rear bearing race into differential carrier with ST1 and ST2.
ST1 398477701 HANDLE

ST2 398477703 DRIFT 2

Fig 2: Pressing Rear Bearing Race Into Differential Carrier With Handle ST1 398477701 And Drift 2 ST2 398477703
Courtesy of SUBARU OF AMERICA, INC.
Install the front bearing race to differential carrier using ST1 and ST2.
ST1 398477701 HANDLE

ST2 398477702 DRIFT
Measure and record the thickness of pinion height Adjusting washer.
NOTE: If tooth contact (drive pinion, hypoid driven gear) is normal in the inspection before disassembling, verify that the washer is not deformed, and then reuse the used washer.
Insert the ST1 into carrier with pinion height adjusting washer and rear bearing cone fitted onto it.
NOTE: Use new rear bearing cone.
Install the preload adjusting collar and washer, front bearing cone, ST2, companion flange, and washer and drive pinion nut.
ST1 398507702 DUMMY SHAFT

ST2 398507703 DUMMY COLLAR

Fig 3: Installing Preload Adjusting Collar, Front Bearing Cone, Washer And Drive Pinion Nut Using Dummy Shaft ST1 398507702 And Dummy Collar ST2 398507703
Courtesy of SUBARU OF AMERICA, INC.

Turn the ST1 with hand to make it seated, and tighten the self-locking nut while measuring the preload with spring balance. Select the preload adjusting washer and collar so that the specified preload is obtained when nut is tightened to the specified torque.

Fig 4: Measuring Preload With Spring Balance

Courtesy of SUBARU OF AMERICA, INC.

NOTE:

Use a new self-locking nut.
Be careful not to give excessive preload.
When tightening the self-locking nut, lock ST1 with ST2 as shown in the figure.
Measure the preload in direction of tangent to flange.

ST1 398507702 DUMMY SHAFT

ST2 398507704 BLOCK

Tightening torque:

181 N.m (18.5 kgf-m, 134 ft-lb)

Fig 5: Locking Dummy Shaft ST1 398507702 With Block ST2 398507704

Courtesy of SUBARU OF AMERICA, INC.

BEARING PRELOAD SPECIFICATIONS

Drive pinion bearing preload

18.1 - 38.8 N (1.8 - 4.0 kgf, 4.1 - 8.7 lb) at companion flange bolt hole

Fig 6: Measuring Preload In Direction Of Tangent To Flange

Courtesy of SUBARU OF AMERICA, INC.

PRELOAD ADJUSTING WASHER AND COLLAR SPECIFICATIONS

Preload adjusting washer	Part No.	Thickness mm (in)
	383705200	2.59 (0.1020)
	383715200	2.57 (0.1012)
	383725200	2.55 (0.1004)
	383735200	2.53 (0.0996)
	383745200	2.51 (0.0988)
	383755200	2.49 (0.0980)
	383765200	2.47 (0.0972)
	383775200	2.45 (0.0965)
	383785200	2.43 (0.0957)
	383795200	2.41 (0.0949)
	383805200	2.39 (0.0941)
	383815200	2.37 (0.0933)
	383825200	2.35 (0.0925)
	383835200	2.33 (0.0917)
	383845200	2.31 (0.0909)
Preload adjusting collar	Part No.	Length mm (in)
	383695201	56.2 (2.213)
	383695202	56.4 (2.220)
	383695203	56.6 (2.228)
	383695204	56.8 (2.236)
	383695205	57.0 (2.244)
	383695206	57.2 (2.252)

Adjusting drive pinion height:

Adjust the drive pinion height with washer installed between the rear bearing cone and the back of pinion gear.

Install the ST2.
ST1 398507702 DUMMY SHAFT

ST2 398507701 DIFFERENTIAL CARRIER GAUGE

ST3 398507703 DUMMY COLLAR

Fig 7: Installing Differential Carrier Gauge ST2 398507701
Courtesy of SUBARU OF AMERICA, INC.
Measure the clearance N between the end of ST2 and the end surface of ST1 by using a thickness gauge.
NOTE: Make sure there is no clearance between the case and ST2.

ST1 398507702 DUMMY SHAFT

ST2 398507701 DIFFERENTIAL CARRIER GAUGE

Fig 8: Measuring Clearance N Between End Of Differential Carrier Gauge ST2 398507701 And End Surface Of Dummy Shaft ST1 398507702
Courtesy of SUBARU OF AMERICA, INC.

Obtain the thickness of pinion height adjusting washer to be inserted from the following formula, and replace the temporarily installed washer with this one.

T = To + N - (H x 0.01) - 0.20 mm

NOTE: Use copies of this page.

FORMULA SPECIFICATIONS

T	Thickness of pinion height adjusting washer mm (in)
To	Thickness of washer temporally inserted mm (in)
N	Clearance of thickness gauge mm (in)
H	Figure marked on drive pinion head
Memo:

(Example of calculation)

To = 2.20+1.20 = 3.40 mm

N = 0.23 mm

H = + 1

T = 3.40 + 0.23 - 0.01 - 0.20 = 3.42

Result: Thickness = 3.42 mm

Therefore use the pinion height adjusting washer of part number 383605200.

PINION HEIGHT ADJUSTING WASHER SPECIFICATIONS

Pinion height adjusting washer
Part No.	Thickness mm (in)
383495200	3.09 (0.1217)
383505200	3.12 (0.1228)
383515200	3.15 (0.1240)
383525200	3.18 (0.1252)
383535200	3.21 (0.1264)
383545200	3.24 (0.1276)
383555200	3.27 (0.1287)
383565200	3.30 (0.1299)
383575200	3.33 (0.1311)
383585200	3.36 (0.1323)
383595200	3.39 (0.1335)
383605200	3.42 (0.1346)
383615200	3.45 (0.1358)
383625200	3.48 (0.1370)
383635200	3.51 (0.1382)
383645200	3.54 (0.1394)
383655200	3.57 (0.1406)
383665200	3.60 (0.1417)
383675200	3.63 (0.1429)
383685200	3.66 (0.1441)

Install the selected pinion height adjusting washer on drive pinion, and press the rear bearing cone into position with ST.
ST 398177700 INSTALLER

Fig 9: Pressing Rear Bearing Cone Into Position With Installer ST 398177700
Courtesy of SUBARU OF AMERICA, INC.
Insert the drive pinion into differential carrier, install the selected bearing preload adjusting collar and washer.

Fig 10: Inserting Drive Pinion Into Differential Carrier
Courtesy of SUBARU OF AMERICA, INC.
Press-fit the front bearing cone into case with
ST1, ST2 and ST3.

ST1 398507703 DUMMY COLLAR

ST2 399780104 WEIGHT

ST3 899580100 INSTALLER

Fig 11: Press-Fitting Front Bearing Cone Into Case
Courtesy of SUBARU OF AMERICA, INC.
Insert the collar, then press-fit the pilot bearing with ST1 and ST2.
ST1 399780104 WEIGHT

ST2 899580100 INSTALLER

Fig 12: Press-Fitting Pilot Bearing With Weight ST1 399780104 And Installer ST2 899580100
Courtesy of SUBARU OF AMERICA, INC.
Fit a new oil seal with ST.
NOTE:
- Press-fit until end of oil seal is 1 mm (0.04 in) inward from end of carrier.
- Apply grease to the oil seal lips.
ST 498447120 INSTALLER

Fig 13: Fitting Oil Seal With Installer ST 498447120
Courtesy of SUBARU OF AMERICA, INC.
Press-fit the companion flange with ST1 and ST2.
NOTE: Be careful not to damage the bearing.

ST1 899874100 INSTALLER

ST2 399780104 WEIGHT

Fig 14: Press-Fitting Companion Flange With Installer ST1 899874100 And Weight ST2 399780104
Courtesy of SUBARU OF AMERICA, INC.
Install a new self-locking nut and secure the companion flange using ST and tighten the nut.
ST 498427200 FLANGE WRENCH

Tightening torque:

181 N.m (18.5 kgf-m, 134 ft-lb)

Fig 15: Installing Self-Locking Nut Using Flange Wrench ST 498427200
Courtesy of SUBARU OF AMERICA, INC.

Assembling differential case

Install the side gears and pinion mate gears, with their thrust washers and pinion mate shaft, into differential case. (Model without LSD)

NOTE:

Apply gear oil on both sides of the washer and on the side gear shaft before installing.
Insert the pinion mate shaft into the differential case by aligning the lock pin holes.

Fig 16: Assembling Differential Case
Courtesy of SUBARU OF AMERICA, INC.

Measure the side gear backlash.
Side gear backlash:

0.10 - 0.20 mm (0.0039 - 0.0079 in)

Fig 17: Measuring Side Gear Backlash
Courtesy of SUBARU OF AMERICA, INC.

Adjust the side gear backlash as specified by selecting side gear thrust washer.

SIDE GEAR THRUST WASHER SPECIFICATIONS

Side gear thrust washer
Part No.	Thickness mm (in)
383445201	0.75- 0.80 (0.0295 - 0.0315)
383445202	0.80- 0.85 (0.0315 - 0.0335)
383445203	0.85 - 0.90 (0.0335 - 0.0354)

Check the condition of rotation after applying oil to the gear tooth surfaces and thrust surfaces.
After inserting the pinion shaft lock pin into differential case, stake the both sides of the hole to prevent pin from falling off.

Install the hypoid driven gear to differential case.
NOTE:
- Before installing bolts, apply LOCITITE to bolt threads.
LOCITITE:

THREE BOND 1324 (Part No. 004403042)
- Tighten diagonally while tapping the bolt heads.
Tightening torque:

105 N.m (10.7 kgf-m, 77.4 ft-lb)

Fig 18: Installing Hypoid Driven Gear To Differential Case
Courtesy of SUBARU OF AMERICA, INC.
Press the side bearing into differential case using ST.
ST 398227700 DRIFT

Fig 19: Pressing Side Bearing Into Differential Case Using Drift ST 398227700
Courtesy of SUBARU OF AMERICA, INC.
Press-fit the side bearing cone to the side bearing retainer using ST.
ST 398437700 DRIFT

Adjusting the side bearing retainer shims

The hypoid driven gear backlash and side bearing preload can be adjusted by the side bearing retainer shim thickness.
Install the differential assembly into differential carrier in the reverse order of disassembly.

Fig 20: Installing Differential Assembly Into Differential Carrier
Courtesy of SUBARU OF AMERICA, INC.

Install the side bearing retainer shims to retainers RH and LH from which they were removed.

NOTE: Replace the broken or corroded side retainer shim with a new one of same thickness.

SIDE BEARING RETAINER SHIM SPECIFICATIONS

Side bearing retainer shim
Part No.	Thickness mm (in)
383475201	0.20 (0.0079)
383475202	0.25 (0.0098)
383475203	0.30 (0.0118)
383475204	0.40 (0.0157)
383475205	0.50 (0.0197)

Align the arrow mark on differential carrier with the mark on side retainer during installation.
NOTE: Be careful that side bearing outer race is not damaged by bearing roller.

Fig 21: Aligning Arrow Mark On Differential Carrier With Mark On Side Retainer
Courtesy of SUBARU OF AMERICA, INC.
Tighten the side bearing retainer bolts.
Tightening torque:

10.3 N.m (1.05 kgf-m, 7.6 ft-lb)

Fig 22: Identifying Side Bearing Retainer Bolts
Courtesy of SUBARU OF AMERICA, INC.
Measure the hypoid driven gear-to-drive pinion backlash. Set the magnet base on differential carrier. Align the contact point of dial gauge with tooth face of hypoid driven gear, and move the hypoid driven gear while holding drive pinion still. Read the value indicated on dial gauge. If the backlash is not within specification, adjust the side bearing retainer shim as follows.
- When backlash is more than 0.2 mm (0.0079 in):
  Reduce shim thickness of behind hypoid driven gear, and increase shim thickness of hypoid driven gear side.
- When backlash is less than 0.1 mm (0.0039 in):
  Increase shim thickness of behind hypoid driven gear, and reduce shim thickness of hypoid driven gear side.
Backlash:

0.10 - 0.20 mm (0.0039 - 0.0079 in)

Fig 23: Measuring Hypoid Driven Gear-To-Drive Pinion Backlash
Courtesy of SUBARU OF AMERICA, INC.
At the same time, measure the total preload of drive pinion. Compared with the resistance when differential case is not installed, if the total preload is not within specification, adjust the thickness of side bearing retainer shims, increasing/reducing by an even amount at a time.

Total preload:

20.7 - 54.4 N (2.1 - 5.5 kgf, 4.7 - 12.2 lb)

Recheck the hypoid driven gear to drive pinion backlash.
Backlash:

0.10 - 0.20 mm (0.0039 - 0.0079 in)

Fig 24: Rechecking Hypoid Driven Gear To Drive Pinion Backlash
Courtesy of SUBARU OF AMERICA, INC.
Check the hypoid driven gear runout on its back surface, and make sure that pinion and hypoid driven gear rotates smoothly.
If the hypoid driven gear runout on its back surface exceed the specification, verify that there is any foreign material between hypoid driven gear and differential case, and they are not deformed.

Hypoid driven gear runout on its back surface: 0.05 mm (0.0020 in)

Fig 25: Checking Hypoid Driven Gear Runout On Its Back Surface
Courtesy of SUBARU OF AMERICA, INC.
Checking and adjusting the tooth contact of hypoid driven gear
1. Apply an even coat of red lead on both sides of three or four teeth on the hypoid driven gear. Check the contact pattern after rotating the hypoid driven gear several revolutions back and forth until a definite contact pattern appears on the hypoid driven gear.
2. When the contact pattern is incorrect, readjust.
NOTE: Be sure to wipe off red lead completely after adjustment is completed.
- Correct tooth contact
Checking item: Tooth contact pattern is slightly shifted toward toe side under no-load rotation. [When loaded, contact pattern moves toward heel.]

Fig 26: Identifying Correct Tooth Contact
Courtesy of SUBARU OF AMERICA, INC.
- Face contact
Checking item: Backlash is too large.

Contact pattern

Fig 27: Identifying Face Contact
Courtesy of SUBARU OF AMERICA, INC.

Corrective action: Increase thickness of drive pinion height adjusting washer in order to bring drive pinion close to hypoid driven gear.

Fig 28: Identifying Corrective Action - Increase Thickness Of Drive Pinion Height Adjusting Washer
Courtesy of SUBARU OF AMERICA, INC.
- Flank contact
Checking item: Backlash is too small.

Contact pattern

Fig 29: Identifying Flank Contact
Courtesy of SUBARU OF AMERICA, INC.

Corrective action: Reduce thickness of drive pinion height adjusting washer in order to bring drive pinion away from hypoid driven gear.

Fig 30: Identifying Corrective Action - Reduce Thickness Of Drive Pinion Height Adjusting Washer
Courtesy of SUBARU OF AMERICA, INC.
- Toe contact (inside end contact)
Checking item: Contact areas is small

Contact pattern

Fig 31: Identifying Toe Contact (Inside End Contact)
Courtesy of SUBARU OF AMERICA, INC.

Corrective action: Reduce thickness of drive pinion height adjusting washer in order to bring drive pinion away from hypoid driven gear.

Fig 32: Identifying Corrective Action - Reduce Thickness Of Drive Pinion Height Adjusting Washer
Courtesy of SUBARU OF AMERICA, INC.
- Heel contact (outside end contact)
Checking item: Contact areas is small

Contact pattern

Fig 33: Identifying Heel Contact (Outside End Contact)
Courtesy of SUBARU OF AMERICA, INC.

Corrective action: Increase thickness of drive pinion height adjusting washer in order to bring drive pinion close to hypoid driven gear.

Fig 34: Identifying Corrective Action - Increase Thickness Of Drive Pinion Height Adjusting Washer
Courtesy of SUBARU OF AMERICA, INC.
If proper tooth contact is not obtained, once again adjust the drive pinion height by changing RH and LH side bearing retainer shims and the hypoid gear backlash.
Remove the RH and LH side bearing retainer.
Install a new O-ring to side bearing retainer of both side.
Using the ST, install the oil seal to the side bearing retainer of both side.
ST 398437700 DRIFT
Align the arrow mark on differential carrier with the mark on side retainer during installation.

Fig 35: Aligning Arrow Mark On Differential Carrier With Mark On Side Retainer
Courtesy of SUBARU OF AMERICA, INC.
Tighten the side bearing retainer bolts.
Tightening torque:

10.3 N.m (1.05 kgf-m, 7.6 ft-lb)

Fig 36: Identifying Side Bearing Retainer Bolts
Courtesy of SUBARU OF AMERICA, INC.
Install the new gasket and rear cover to the differential carrier, and tighten the bolts to specified torque.
Tightening torque:

29 N.m (3.0 kgf-m, 21.7 ft-lb)

Fig 37: Installing Rear Cover To Differential Carrier
Courtesy of SUBARU OF AMERICA, INC.
Install the breather cap.
Install the drain plug and filler plug.
Tightening torque:

49 N.m (5.0 kgf-m, 36.2 ft-lb)