1998 MITSUBISHI MONTERO differential

TESTING & INSPECTION
AXLE SHAFT END PLAY
Montero & Montero Sport
Using dial indicator, check axle shaft end play. End play
should be .010" (.25 mm). If end play is not within specification,
replace axle bearing. See AXLE SHAFT OVERHAUL under OVERHAUL.
AXLE TOTAL BACKLASH
1) Raise and support rear axle. Place transmission in
Neutral. Apply parking brake. Rotate drive shaft clockwise. Place
reference marks on pinion dust cover and differential housing.
2) Rotate drive shaft counterclockwise, and measure distance
between reference marks. Differential must be removed and backlash
adjusted if distance exceeds 0.2" (5 mm). See RING GEAR BACK-LASH
procedure under DIFFERENTIAL ASSEMBLY (LIMITED SLIP) under OVERHAUL.
LIMITED SLIP DIFFERENTIAL PRELOAD
1) Place transmission in Neutral. Block front wheels. Raise
one rear wheel off ground and remove wheel. Release parking brake.
2) Using torque wrench and axle puller adapter, measure
starting torque while rotating wheel in forward direction. See Fig. 1.
Differential must be repaired if torque is less than 18 ft. lbs. (25
N.m).
Fig. 1: Testing Limited Slip Differential Preload
Courtesy of Mitsubishi Motor Sales of America.
LOCKING DIFFERENTIAL (MONTERO)
Air Pump

Connect air pressure gauge in-line to air hose from air pump.
Air pump is located in right storage area, under rear seat. Connect
battery voltage to air pump (positive lead to Red wire). The air pump
is operating correctly when the following sequences occur;
* Pump should operate for no more than 5 seconds.
* Pressure should be 4-6 psi (.28-.41 kg/cm
) within 10-20
seconds after pump has stopped.
* After air pump has stopped operating, it should not restart
operating for 5 minutes.
Center Differential Lock Operation Switch
See ANTI-LOCK BRAKE SYSTEM article in BRAKES.
Differential Lock Switch
Remove switch from center console. To test switch operation,
see Fig. 2 . Replace switch as needed.
Differential Lock Control Unit
See ANTI-LOCK BRAKE SYSTEM article in BRAKES.
Lock Detection Switch
1) Raise and support vehicle. Disconnect air hose connection
near rear differential. Connect air source with pressure regulator and
pressure gauge. Apply 4 psi (.28 kg/cm
) pressure. Disconnect lock
detection switch harness connector.
2) Using ohmmeter, check if continuity exists with air
pressure applied. Continuity should exist with air pressure applied.
If continuity exists, ensure axle is locked by attempting to turn rear
wheels separately of each other.
3) If continuity does not exist, go to step 4). If continuity\
does exist but axles are not locked, see CARRIER ASSEMBLY under
REMOVAL & INSTALLATION and inspect locking assembly.
4) Remove detection switch from housing. Using ohmmeter,
check continuity of switch. Continuity should exist with switch
plunger extended. With plunger in neutral position, continuity should
not exist. Replace switch as needed.
Fig. 2: Checking Differential Lock Switch Continuity
Courtesy of Mitsubishi Motor Sales of America.
REMOVAL & INSTALLATION

into left side axle housing. Install left axle shaft assembly into
axle housing, and tighten nuts to specification. See
TORQUE SPECIFICATIONS.
2) Install right axle shaft assembly into axle housing
without shim or "O" ring. Temporarily tighten nuts in diagonal
sequence to 51.6 INCH lbs. (5.8 N.m) in 2 stages. Measure clearance
between bearing case of right axle and rear axle housing end with
feeler gauge.
3) Select shims equal to sum of measured clearance plus .002-
.008" (.05-.20 mm). Remove right axle shaft, and install selected
shim(s) and "O" ring into right axle housing end. Install right axle
shaft assembly into rear axle housing. Tighten nuts in diagonal
sequence to specification. See TORQUE SPECIFICATIONS.
4) Using dial indicator, check end play of axle shaft. End
play should be .002-.008" (.05-.20 mm). If end play is not within
specification, change shim(s) to obtain correct end play. Reverse
removal procedure to install remaining components. Adjust parking
brake, and bleed brake system.
CARRIER ASSEMBLY
Removal
Raise and support vehicle. Drain gear oil. Mark drive shaft
flange-to-pinion flange position. Remove drive shaft. Remove axle
shafts. See AXLE SHAFT R & I . Support differential carrier with jack.
Remove differential carrier retaining nuts. Remove differential
carrier.
Inspection
Check for leaks at vent plug, differential carrier companion
flange and where carrier joins axle housing.
Installation
Apply sealant to axle housing surface. To install, reverse
removal procedure. Align marks on drive shaft and pinion flange.
DRIVE SHAFT
Removal
Make match marks on drive shaft yoke flange and pinion
flange. Remove bolts and drive shaft from vehicle.
Installation
To install, reverse removal procedure. Ensure match marks are
aligned. Tighten bolts to specification. See TORQUE SPECIFICATIONS.
OVERHAUL
AXLE SHAFT OVERHAUL
Removal
1) Secure axle shaft assembly in a vise, and remove one
retainer bolt from backing plate. Push bearing case completely to side
of dust cover. Place adhesive tape around edge of bearing case at
retainer bolt hole to prevent damage.
CAUTION: DO NOT damage bearing case or axle shaft when grinding or
chiseling retainer ring.
2) Secure axle shaft, and grind retainer ring until retainer
ring wall thickness is .04-.06" (1.0-1.5 mm) on axle shaft side and .
08" (2.0 mm) on bearing side. See Fig. 4.

.060 (1.52) .................................................... Red\
.067 (1.70) ................................................. Purple\
.073 (1.85) ................................................... Blue\
.079 (2.01) ................................................. Yellow\
.085 (2.16) ................................................ Neutral\









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DIFFERENTIAL ASSEMBLY (CONVENTIONAL)
Pre-Disassembly Inspection
1) Secure differential assembly in appropriate holder. Secure
drive pinion from turning. Mount dial indicator on case and check ring
gear backlash at 4 positions. See Fig. 6. Backlash should be .005-.
007" (.13-.18 mm).
2) Remount dial indicator and measure ring gear runout. See
Fig. 7 . On all models, runout should not exceed .002" (.05 mm).
Remount dial indicator and measure pinion gear backlash on models
without limited slip differential. See Fig. 8. Secure side gear from
turning with wedge. Backlash should be 0-.003" (0-.08 mm). Pinion gear\
backlash service limit is .008" (.20 mm).
3) Check gear tooth contact pattern between ring gear and
drive pinion gear. Apply Prussian Blue to both surfaces of ring gear
teeth. Insert brass rod between differential housing and carrier
assembly to provide resistance while turning drive pinion.
4) Turning resistance of drive pinion should be 28-33 INCH
lbs. (2.5-3.0 N.m). Rotate drive pinion until ring gear completes one
revolution. Reverse direction of rotation and return to original
starting point. Check wear pattern. See GEAR TOOTH CONTACT PATTERNS
article in GENERAL INFORMATION.
5) On Montero models with differential lock, connect air
supply hose with pressure gauge and regulator to actuator air pipe.
Apply 4 psi (.28 kg/cm
) of pressure. Using Adapter Shaft (MB990992),
turn side gear on one side of carrier assembly only. Locking mechanism
should engage. To disengage, release air pressure and turn side gear
1/4-1/2 turn.
6) With lock mechanism engaged, measure turning torque of
drive pinion. Turning torque should not be less than 36 ft. lbs. (50
N.m). With lock mechanism disengaged, turning torque should not be
more than 36 ft. lbs. (50 N.m).
Fig. 6: Measuring Ring Gear Backlash
Courtesy of Mitsubishi Motor Sales of America.

Fig. 7: Measuring Ring Gear Runout
Courtesy of Mitsubishi Motor Sales of America.
Fig. 8: Checking Pinion & Side Gear Backlash
Courtesy of Mitsubishi Motor Sales of America.
NOTE: See DIFFERENTIAL ASSEMBLY (LIMITED SLIP) for carrier

assembly and drive pinion installation.
Carrier Assembly & Drive Pinion Removal
1) Remove differential carrier from axle housing. Remove lock
plates. Mark location of side bearing nuts for reassembly. Remove side
bearing nuts. See Fig. 9. Mark location of bearing caps for
reassembly. Remove bearing caps. Remove differential carrier assembly
from differential housing.
Fig. 9: Exploded View Of Conventional Rear Differential (Typical)
Courtesy of Mitsubishi Motor Sales of America.
2) Secure drive pinion companion flange from turning. Remove
companion flange retaining nut. Scribe alignment marks on drive pinion
and companion flange for reassembly. Using soft-face hammer, drive
pinion out of housing. Remove front adjusting shim and spacer from
pinion.
3) Using bearing splitter and press, remove rear bearing from
pinion. Remove rear adjusting shim from drive pinion. Remove oil seal
and bearing races from differential housing.
Disassembly (Carrier Assembly)
1) Using bearing splitter and press, remove differential case
side bearings. Place alignment marks on ring gear and differential
case for reassembly. Loosen ring gear bolts in diagonal sequence.
Remove ring gear.
2) Remove pinion shaft lock pin from differential carrier.
Remove differential pinion shaft and thrust block (if equipped).
Remove pinion gears and washers. Remove side gears and thrust spacers.
Mark components for reassembly reference.
Inspection
Wash parts in clean solvent and dry with compressed air.
Inspect bearings for discoloration and/or flaking. Check all gears for
irregular wear or damage. Ring gear and drive pinion must be replaced

as matched set. Side gears and pinion gears must be replaced as
matched set.
Reassembly & Adjustment
1) Install thrust spacers, side gears, pinion washers and
pinion gears in differential case. DO NOT install thrust block (if
equipped) at this time.
2) Install pinion shaft without lock pin. Check pinion and
side gear backlash. Install wooden wedge to lock side gears. See
Fig. 8 . Using dial indicator, measure gear backlash. Backlash should
be .0004-.0030" (.010-.080 mm). Service limit is .008" (.20 mm).
3) Adjust backlash by using different side gear spacers.
Ensure both sides are equally shimmed. Install thrust block (if
equipped) once correct backlash is obtained. Install pinion shaft lock
pin from ring gear side of carrier housing. Securely stake pin in 2
places. Ensure adhesive is removed from ring gear mounting bolts and
gear mounting surface. Clean internal threads with tap.
4) Ensure alignment marks on differential case and ring gear
align. Apply Loctite 271 to bolts, and install ring gear on
differential case. Tighten bolts in diagonal sequence to
specification. See TORQUE SPECIFICATIONS . Using appropriate adapter,
press on carrier side bearings.
DIFFERENTIAL ASSEMBLY (LIMITED SLIP)
NOTE: Manufacturer does not provide disassembly or reassembly
procedures for locking type differential. Use illustrations
for exploded views of assembly. See Figs. 11 and 12.
NOTE: See PRE-DISASSEMBLY INSPECTION under
DIFFERENTIAL ASSEMBLY (CONVENTIONAL) before disassembling
carrier assembly. For carrier assembly and drive pinion
removal, see DIFFERENTIAL ASSEMBLY (CONVENTIONAL) .
Disassembly
1) Once ring gear is removed, loosen carrier housing screws
in diagonal pattern. Separate cases and remove components. See Fig. 10
. Maintain parts in order of disassembly. Clean all parts in new
solvent.
2) Inspect condition of friction and spring plates and
friction discs. Replace disc and/or plates if worn or heat damaged.
Distortion of discs will cause incorrect clutch pressure. Scratches,
nicks or burrs on components can be repaired with an oil stone.
3) Discs must be flat and free of distortion. Check discs on
surface plate with dial indicator. Maximum warpage of friction plate
or disc is .003" (.08 mm). Inspect thickness of discs and plates.
Thickness limit between discs and plates is .004" (.10 mm).
Fig. 10: Exploded View Of Limited Slip Differential
Courtesy of Mitsubishi Motor Sales of America.

Fig. 11: Exploded View Of Locking Differential Actuator Assembly
Courtesy of Mitsubishi Motor Sales of America.