1991 MITSUBISHI 3000GT wheel

li
LREAR AXLE
- Troubleshootinn
TROUBLESHOOTINGM27EAAH
SymptomProbable cause
Remedy
4XLE SHAFT
Noise while wheelsBrake drag
Replace
are rotatingBent axle shaftWorn or scarred axle shaft bearing
Grease leakageWorn or damaged oil seal
Malfunction of bearing sealReplace
DRIVE SHAFTNoiseWear, play or seizure of ball jointExcessive drive shaft spline loosenessReplace
DIFFERENTIAL
(LIMITED SLIP
DIFFERENTIAL)Abnormal noise
during driving
or gear changing
NOTE
Excessive final drive gear backlashInsufficient drive pinion preload
Excessive differential gear backlash
Worn
spline of a side gear
Loose companion flange self-locking nut
Adjust
Adjust or replace
Replace
Retighten or replace
In addition to a malfunction of the differential carrier components, abnormal noise can also be caused by the
universal joint of the propeller shaft, the axle shafts, the wheel bearings, etc. Before disassembling any parts, takeall possibilities into consideration and confirm the source of the noise.
Abnormal noisewhen cornering
Gear noiseDamaged differential gears
Damaged pinion shaft
Insufficient gear oil quantity
Improper final drive gear tooth contact
adjustment
Replace
Replenish
Adjust or replace
Incorrect final drive gear backlash
Improper drive pinion preload adjustmentAdjust
Damaged, broken, and/or seized tooth surfacesof the drive gear and drive pinionDamaged, broken, and/or seized drive pinion
bearingsReplace
Damaged, broken, and/or seized side bearings
Damaged differential case
inferior gear oil
NOTE
Insufficient gear oil quantityReplenishNoise from the engine, muffler vibration, transaxle, propeller shaft, wheel bearings, tires, body, etc., is easily
mistaken as
being caused by malfunctions in the differential carrier components. Be extremely careful and
attentive when performing the driving test, etc.
Test methods to confirm the source of the abnormal noise include: coasting, acceleration, constant speed driving.
raising the rear wheels
on a jack, etc. Use the method most appropriate to the crrcumstances.TSB Revision

REAR AXLE - Service Adjustment Procedures2743
,,rmr
SERVICE ADJUSTMENT PROCEDURES
REAR AXLE TOTAL BACKLASH CHECKM27FAAG
If the vehicle vibrates and produces a booming sound due to an
imbalance of the driving system, measure the rear axle total
backlash by the following procedures to see if the differential
carrier assembly required removal.
(1) Place the gearshift lever in the neutral position, apply the
parking brake and jack up the vehicle.
(2) Manually turn the propeller shaft clockwise as far as it will
go and make mating marks on the companion flange dustshield and the differential carrier.
(3) Manually turn the propeller shaft counterclockwise as far as
it will go and measure the movement of the mating marks.Limit: 5 mm
(.2 in.)
(4) If the backlash exceeds the limit, remove the differential
carrier assembly and adjust the backlash. (Refer to P.27-26.)
GEAR OIL LEVEL CHECKM27FCAG1. Remove the filler plug, and check the oil level.
2. The oil level is sufficient if it reaches the filler plug hole.
Specified
gear oil:
Hypoid Gear Oil API classification GL-5 or higher
[l.l liter (1.2 q&J]
NOTEAbove -23°C (-10°F): SAE 90,
85W-90, 8OW-90From -34°C (-30°F) to -23°C (-10°F): SAE
8OW, 8OW-90Below -34°C (-30°F): SAE 75W
REAR WHEEL BEARING END PLAY CHECKM27FBAF1. Support the vehicle on axle stands positioned at the
specified locations and remove the rear wheel.
2. Separate the parking brake cable from the rear brake.
3. Remove the caliper assembly and brake disc.
4. Place a dial gauge as shown in the illustration, and then
measure the play when the axle shaft is moved in the axial
direction.Limit: 0.8 mm
(.031 in.)
5.If the play exceeds the limit, check the tightening torque ofthe companion flange of the axle shaft; if it is correct,
replace the wheel bearing.
1 TSB RevisionI

27-14REAR AXLE - Service Adjustment Procedures~
Incorrect
llA033CREAR WHEEL BEARING ROTATION TORQUE
I
CHECKM27FJAB1. Remove the drive shaft from the companion flange.
2. Remove the brake pad or caliper assembly.
3. Attach a spring balance to the hub bolt, then, pulling the
‘d ’balance at a right angle to the hub bolt, measure the
rotation torque (rotation starting torque) to see whether it iswithin the standard value.
Standard value: 12 N (2.6 Ibs.) [rotation starting torque0.7 Nm (6
in.lbs.)] or less
4. If the rotation starting torque exceeds the standard value,
check the tightening torque of the axle shaft companion
flange. If it is normal, replace the bearing.
LIMITED-SLIP DIFFERENTIAL CHECKM27FlAB
1.Block the front wheels and move the shift lever to neutral.2. Completely release the parking brake.
3. Jack up the rear wheels and place a rigid rack at the
specified part of the side sill.
4. Disconnect the coupling of the differential and propeller
shaft.LJ5. When one wheel is slowly rotated, check whether or not
the wheel on the other side turns in the same direction.
6.If it turns in the opposite direction, replace the viscous unit.
1 TSB Revision

27-16
REAR AXLE - Axle Shaft
MB990241-01
MB990,938-01AY ho"sing
MB990$28-0111 A003865. REMOVAL OF SELF-LOCKING NUT
With the special tool, secure the axle shaft and remove the
companion flange self-locking nut.8. REMOVAL OF AXLE SHAFT ASSEMBLY
With the special tool, remove the axle shaft from the axle
housing.
9.REMOVAL OF REAR ROTOR Remove the rear rotor from the axle shaft.
10. REMOVAL OF OUTER BEARING / 1.1. DUST SHIELDRemove the outer bearing and dust shield concurrently
from the axle shaft.
14. REMOVAL OF OIL SEAL
/ 15. INNER BEARING
With the special tool, remove the inner bearing and oil sealfrom the axle housing.
INSPECTIONhl27HcAGl Check the companion flange for wear or damage.
l Check the dust shield for deformation or damage.
l Check the wheel bearings for burning or discoloration.
l Check the wheel bearing for unsmooth rotation.
l Check the axle shaft for cracking, wear or damage.
l Check oil seal for cracking or damage.
TSB Revision

27-24REAR AXLE - Differential Carrier
DIFFERENTIAL CARRIER
REMOVAL AND INSTALLATION
M271A. -
Pre-removal and Post-installation Operationl Draining and Filling of Differential Gear Oil
(Refer to Group 00 - Maintenance Service.)l Removal and Installation of Main Muffler
(Refer to Group 15 - Exhaust Pipe and Muffler.)24Nm
17 ft.lbs.
90 Nm65 ft.lbs.4
/lIl8
c/
90 Nm65 ft.lbs.
63
i
i !f%
43 - 51ft.lbs.
90 Nm65 ftlbs.
,55-65Nm40 - 47 fklbs.
22 - 25 ft.lbs.
90 Nm65 ft.lbs.llFO034
Removal steps
a*1. Drive shaft
2. Circlipl * l a3. Propeller shaft connection
4. Differential support assembly
5. Differential support member assembly
6. Rear wheel oil pump installation bolt
l * l *7. Differential carrier
8. O-ring
1 TSB Revision

REAR AXLE - Differential Carrier
27-25
Mating marks
//
MB991 153
MBggo8477J=f 4
Differential support member
llNOOl1
DifferentialllN0053
SERVICE POINTS OF REMOVALm27wAm
1. REMOVAL OF DRIVE SHAFT
With a tire lever, etc., remove the drive shaft from the
differential carrier.
NOTE
Be cautious to ensure that the differential carrier oil seal isnot damaged by the drive shaft spline.
3. DISCONNECTION OF PROPELLER SHAFT
(1) Make mating marks on the differential companion
flange and the propeller shaft flange yoke for reference
during reassembly.
(2) Remove the differential carrier and propeller shaft
connection.
(3) Support the propeller shaft with wire.
7. REMOVAL OF DIFFERENTIAL CARRIER
Holding the bottom of the differential carrier and removing
the rear wheel oil pump through the mounting hole, removethe differential carrier.
Caution1. Use care not to damage the rear wheel oil pump
gears.
2.Use care not to allow dirt or foreign matter to fall
into the differential carrier.
DIFFERENTIAL SUPPORT BUSHING AND DIF-
FERENTIAL SUPPORT MEMBER BUSHING RE-
PLACEMENTM271YAB
Install or remove the bushing using the special tool. Install the
bushing with its hollow portion facing in the direction shown.
CautionInstall the bushing with the differential support and
differential support member chamfered end first and
install until the bushing outer case end face is flush withthe support and support member.

27-26
REAR AXLE - Differential Carrier
SERVICE POINTS OF INSTALLATION
7. INSTALLATION OF DIFFERENTIAL CARRIERm27lDAL
Install the rear wheel oil pump by inserting it through the
mounting hole and install the differential carrier securely.\yiIlYl61
Caution
Use care not to damage the rear wheel oil pump gears.
3. CONNECTION OF PROPELLER SHAFTAlign the mating marks on the flange yoke and the
companion flange to install the propeller shaft.
INSPECTION BEFORE DISASSEMBLYM27lEAJHold the working base in a vice, and attach the differential
carrier to the working base.
FINAL DRIVE GEAR BACKLASH
With the drive pinion locked in place, measure the final drivegear backlash with a dial indicator on the drive gear.
NOTEMeasure at four points or more on the circumference of the
drive gear.d’Standard value: 0.11
- 0.16 mm (.004 - .006 in.)IDRIVE GEAR
RUNOUTI
Measure the drive gear runout at the shoulder on the reverseside of the drive gear.
Limit: 0.05 mm
(.002 in.)
FINAL DRIVE GEAR TOOTH CONTACT
Check the final drive gear tooth contact by following the steps
below.
(1) Apply a thin, uniform coat of machine blue to both surfaces ’of the drive gear teeth.
TSB Revision

REAR AXLE - Differential Carrier
27-33
Lubrication, Sealing and Adhesion Points
L
11lwO.llFOO11
Sealant: 3M AID Part No. 8663 or equivalentllFO032
Adhesive: 3M Stud Locking Part
No. 4170 or equivalent
Spring pinDjive gear
View A
ilA0262llA0261
SERVICE POINTS OF REASSEMBLYM27UBG
1. INSTALLATION OF SPRING PIN (FOR
4WS)
Tap the spring pin into the differential case to the position
shown in the illustration before
press fitting the rear wheel
oil pump drive gear. The notch on the spring pin should bein the position shown in the illustration.
TSB Revision