Differentials: Overhaul Saab 9-2X I

DISASSEMBLY

To detect the real cause of trouble, inspect the following items before disassembling.

1. Tooth contact of hypoid driven gear and pinion, and backlash
2. Runout of hypoid driven gear at its back surface
3. Turning resistance of drive pinion

Set the ST on vise and install the differential assembly to ST.

ST 32005055 ATTACHMENT

Scheme 41

Drain the gear oil by removing the plug.

Remove the air breather cap.

Note. Do not attempt to remove the air breather cap if unnecessary. When removing the air breather cap, replace the air breather cap with a new one.

Scheme 42

1. Air breather cap
2. Rear cover

Remove the bolts, and then remove the rear cover.

Note. Remove it by tapping with plastic hammer.

Scheme 43

1. Rear cover
2. Differential carrier

Make right and left side bearing retainers in order to identify them at reassembly. Remove the side bearing retainer attaching bolts, set the ST to differential case, and extract right and left side bearing retainers with a puller.

Note. Each shim, which is installed to adjust the side bearing preload, should be kept together with its mating retainer.

ST 32005059 ATTACHMENT

Scheme 44

Pull out the differential case assembly from differential carrier.

Note. Be careful not to hit the teeth against the case.

Scheme 45

When replacing the side bearing, pull the bearing cup from side bearing retainer using ST.

ST 32005071 PULLER ASSY

Scheme 46

Extract the bearing cone with ST.

Note. Do not attempt to disassemble the parts unless necessary. Set the puller so that its claws catch the edge of bearing cone. Never mix up the right and left hand bearing races and cones.

ST 32005025 PULLER ASSY

Scheme 47

Remove the hypoid driven gear by loosening the hypoid driven gear bolts.

Scheme 48

Drive out the pinion shaft lock pin from hypoid driven gear side. (Model without LSD)

Note. The lock pin is staked at the pin hole end on the differential carrier; do not drive it out forcibly before unstaking it.

ST 32005181 STRAIGHT PIN REMOVER

Scheme 49

Draw out the pinion mate shaft and remove the pinion mate gears, side gears and thrust washers. (Model without LSD)

Note. The gears as well as thrust washers should be marked or kept separated right and left, front and rear.

Scheme 50

1. Side gear
2. Pinion mate gear
3. Thrust washer
4. Differential case
5. Pinion mate shaft

Hold the companion flange with ST and remove self-locking nut.

ST 32005101 FLANGE WRENCH

Scheme 51

Extract the companion flange with a puller.

Scheme 52

Press the end of drive pinion shaft and extract it together with the rear bearing cone, preload adjusting spacer and washer.

Note. Hold the drive pinion so as not to drop it.

ST 32005060 DRIFT

Scheme 53

Remove the rear bearing cone from drive pinion by supporting the cone with ST.

Note. Place the replacer so that its center-recessed side faces the pinion gear.

ST 32005070 REPLACER

Scheme 54

Remove the front oil seal from differential carrier using ST.

ST 32005071 PULLER ASSY

Scheme 55

Remove the pilot bearing together with front bearing cone and spacer using ST.

ST 32005060 DRIFT

Scheme 56

1. Pilot bearing
2. Spacer
3. Front bearing
4. Rear bearing cup

When replacing the bearings, hit out the front bearing cup and rear bearing cup in this order out of case by using a brass bar.

Scheme 57

1. 2 cutouts along diagonal lines
2. Hit out alternately with brass bar.

ASSEMBLY

Note. Assemble in the reverse order of disassembling. 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 when installing the bearings and thrust washers. Be careful not to mix up the right and left hand races of the bearings. Use a new O-ring and gasket. Replace the oil seal with a new one at every disassembly. Apply chassis grease between the lips when installing the oil seal. Be careful not to confuse the installing direction of oil seal.

Scheme 58

Adjusting preload for front and rear bearings

Adjust the bearing preload with spacer 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 using ST1 and ST2.

ST1 32005061 HANDLE

ST2 32005063 DRIFT 2

Scheme 59

Install the front bearing race to differential carrier using ST1 and ST2.

ST1 32005061 HANDLE

ST2 32005063 DRIFT 2

Insert the ST1 into carrier with pinion height adjusting washer and rear bearing cone fitted onto it.

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 re-use the used washer. Use a new rear bearing cone.

Then install the preload adjusting spacer and washer, front bearing cone, ST2, companion flange, and washer and drive pinion nut.

ST1 32005067 DUMMY SHAFT

ST2 32005068 DUMMY COLLAR

Scheme 60

1. Pinion height adjusting washer
2. Preload adjusting spacer
3. Preload adjusting washer

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 spacer so that the specified preload is obtained when nut is tightened to the specified torque.

Scheme 61

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 32005067 DUMMY SHAFT

ST2 32005069 BLOCK

Tightening torque

181 Nm (18.5 kgf-m, 134 ft-lb)

Scheme 62

DRIVE PINION BEARING PRELOAD

Scheme 63

PRELOAD ADJUSTING WASHER SPECIFICATION

Drive pinion height adjustment

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

Install the ST2.

Note. At this time, install a pinion height adjusting washer which is temporarily selected or the same as that used before. Measure and record the thickness.

ST1 32005067 DUMMY SHAFT

ST2 32005066 DIFFERENTIAL CARRIER GAUGE

ST3 32005068 DUMMY COLLAR

Scheme 64

1. Pinion height adjusting washer

Measure the clearance N between the end of ST2 and end surface of ST1 by using a thickness gauge.

Note. Make sure there is no clearance between the case and ST2.

ST1 32005067 DUMMY SHAFT

ST2 32005066 DIFFERENTIAL CARRIER GAUGE

Scheme 65

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

T = To + N - (H x 0.01) - 0.20 mm (0.0079 in)

Note. Use copies of this page.

SHIM SPECIFICATION

(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 washer 32007036.

ADJUSTING WASHER SPECIFICATION

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

ST 32005054 INSTALLER

Scheme 66

Insert the drive pinion into differential carrier, install the previously selected bearing preload adjusting spacer and washer.

Scheme 67

1. Drive pinion
2. Bearing adjusting spacer
3. Washer
4. Differential carrier

Press-fit the front bearing cone into case with ST1, ST2 and ST3.

ST1 32005068 DUMMY COLLAR

ST2 32005081 WEIGHT

ST3 32005175 INSTALLER

Scheme 68

Insert the spacer, then press-fit the pilot bearing with ST1 and ST2.

ST1 32005081 WEIGHT

ST2 32005175 INSTALLER

Scheme 69

Fit a new oil seal with ST.

Note. Press-fit until the end of oil seal is 1 mm (0.04 in) inward from end of carrier. Apply grease between the oil seal lips.

ST 32005104 INSTALLER

Scheme 70

Press-fit the companion flange with ST1 and ST2.

Note. Be careful not to damage the bearing.

ST1 32005179 INSTALLER

ST2 32005081 WEIGHT

Scheme 71

Install a new self-locking nut. Then tighten it with the ST.

ST 32005101 FLANGE WRENCH

Tightening torque

181 Nm (18.5 kgf-m, 134 ft-lb)

Scheme 72

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.

Scheme 73

Measure the side gear backlash.

Side gear backlash

0.10 - 0.20 mm (0.0039 - 0.0079 in)

Scheme 74

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

THRUST WASHER SPECIFICATION

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 both sides of the hole to prevent pin from falling off.

Install the hypoid driven gear on differential case.

Note. Before installing the bolts, apply Lock Tite to bolt threads.

Lock Tite

THREE BOND 1324 (Part No. 32005016) or equivalent

Note. Tighten diagonally while tapping the bolt heads.

Tightening torque

105 Nm (10.7 kgf-m, 77.4 ft -lb)

Scheme 75

Press the side bearing into differential case using ST.

ST 32005057 DRIFT

Scheme 76

Press the side bearing cone into side bearing retainer using ST.

ST 32005064 DRIFT

Adjusting side bearing retainer shims

The driven gear backlash and side bearing preload can be determined by the side bearing retainer shim thickness.

Install the differential case assembly into differential carrier in the reverse order of disassembly.

Scheme 77

Install the side retainer shims to the right and left retainers from which they were removed.

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

RETAINER SHIM SPECIFICATION

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.

Scheme 78

1. Arrow mark

Tighten the side bearing retainer bolts.

Note. Before tightening the two side bearing retainer bolts, apply Lock Tite to bolt threads.

Lock Tite

THREE BOND 1105 (Part No.32005014) or equivalent

Tightening torque

10.3 Nm (1.05 kgf-m, 7.6 ft-lb)

Scheme 79

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.

Backlash

0.10 - 0.20 mm (0.0039 - 0.0079 in)

Scheme 80

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)

Re-check the hypoid driven gear-to-pinion backlash.

Backlash

0.10 - 0.20 mm (0.0039 - 0.0079 in)

Scheme 81

Check the hypoid driven gear runout on its back surface, and make sure that pinion and hypoid driven gear rotate smoothly.

Limit of runout

Less than 0.05 mm (0.0020 in)

Scheme 82

Checking and adjusting tooth contact of hypoid driven gear

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.

When the contact pattern is incorrect, readjust according to the instructions given in "TOOTH CONTACT PATTERN".

Note. Be sure to wipe off red lead completely after adjustment is completed.

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Scheme 88

Scheme 89

Scheme 90

Scheme 91

1. Correct tooth contact Checking item: Tooth contact pattern is slightly shifted toward to toe side under no-load rotation. (When loaded, contact pattern moves toward heel) Toe side Heel side
2. Face contact Checking item: Backlash is too large. Contact pattern
3. Corrective action: Increase thickness of drive pinion height adjusting washer in order to bring drive pinion close to hypoid driven gear.
4. Flank contact Checking item: Backlash is too small. Contact pattern Corrective action: Reduce thickness of drive pinion height adjusting washer in order to move drive pinion away from hypoid driven gear.
5. Toe contact (Inside end contact) Checking item: Contact area is small. Contact pattern Corrective action: Reduce thickness of drive pinion height adjusting washer in order to move drive pinion away from hypoid driven gear.
6. Heel contact (Outside end contact) Checking item: Contact area is small. Contact pattern Corrective action: Increase thickness of drive pinion height adjusting washer in order to bring drive pinion close to hypoid driven gear.

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 side bearing retainers on right and left side.

Install new O-rings to side bearing retainers on right and left side.

Install the oil seals to side bearing retainers on right and left side.

Align the arrow mark on differential carrier with the mark on side retainer during installation.

Scheme 92

1. Arrow mark

Tighten the side bearing retainer bolts.

Lock Tite

THREE BOND 1105 (Part No. 32005014) or equivalent

Tightening torque

10.3 Nm (1.05 kgf-m, 7.6 ft-lb)

Scheme 93

Install the new gasket and rear cover and tighten the bolts to specified torque.

Tightening torque

29 Nm (3.0 kgf-m, 21.7 ft -lb)

Scheme 94

Install the breather cap.

Install the drain plug and filler plug.

Tightening torque

49 Nm (5.0 kgf-m, 36.2 ft -lb)