Disassembly and Assembly
DISASSEMBLY AND ASSEMBLY
DISASSEMBLY SERVICE POINTS
<> SCREW REMOVAL
1. Check out the alignment marks.
2. Loosen uniformly, little by little the screws securing differential case A to B.
3. Separate differential case B from differential case A and remove their components.
4. Keep the removed spring plates, friction plates, and friction discs organized in order of removal and separated for right and left use.
ASSEMBLY SERVICE POINTS
>>A<< DIFFERENTIAL CASE B INSTALLATION
Before starting the assembly procedure, perform the following steps to adjust dimensional differences (clutch plate friction force) in the axial direction of the components inside the differential case and axial clearance of the differential side gear.
1. Place friction discs (two each) and friction plates (three each) one on top of another as illustrated and, using a micrometer, measure the thickness of each of the right and left assemblies. Select different discs and plates so that the difference between the right and left assemblies falls within the specified range.
Standard value: 0 - 0.05 mm (0 - 0.002 inch)
NOTE: If a new part is used, note that the friction disc comes in two thickness: 1.6 mm (0.063 inch) and 1.7 mm (0.067 inch).
2. Measure the thickness of each of the right and left spring plates.
3. Assemble the pressure ring internal parts (pinion shaft and pressure ring), friction plates, and friction discs and, using a micrometer, measure the overall width.
NOTE: When taking measurements, press the assembly from both sides so that the pinion shaft makes a positive contact with the groove in the pressure ring.
4. Find value (A) which is the thickness measured in step (3) added to the thickness of two spring plates.
5. Find dimension (B) between the spring plate facing surfaces when differential case A and B are assembled together.
B = C + D - E
6. If the clearance between the spring plate and differential case (B - A) is outside the specified range, change the friction discs and make adjustments.
Standard value: 0.06 - 0.25 mm (0.002 - 0.010 inch)
7. Coat each part with the specified gear oil and mount it in the specified direction and order into differential case B.
Hypoid gear oil MITSUBISHI Genuine Gear Oil Part No. 8149630 EX, or equivalent
NOTE: Apply a careful coat of gear oil to the contacting and sliding surfaces.
CAUTION: When installing the pressure ring into the differential case B, the groove should be faced in the direction shown in the figure. Otherwise it may cause a malfunction.
8. Mount each part in the specified direction and order into differential case B.
>>B<< SCREW TIGHTENING
1. Align the alignment mark on differential case A with that on differential case B.
2. Tighten the screws connecting differential case A and B a uniform amount little by little in the diagonal order.
NOTE: If tightening the screws does not bring the two cases properly together, the spring plates are not probably assembled properly. Reassemble from the start.
>>C<< LSD DIFFERENTIAL TORQUE CHECK
1. Use special tools MB990989 and MB990990 to check for differential torque.
Standard value
NOTE: Before measuring the differential torque, first turn the gears so they snug each other, then take measurements during rotation.
2. If the measurement falls outside the specified range, disassemble the differential case assembly and repair or replace defective parts.
INSPECTION
DIFFERENTIAL CASE INTERNAL PARTS CONTACT/SLIDING SURFACE CHECK
1. Clean the disassembled parts with cleaning oil and dry them with compressed air.
2. Check each plate, disc, and pressure ring for the following:
^ A: Friction and sliding surfaces of friction discs, friction plates, and spring plates. Replace a defective part that has heat discoloration and excessive wear, as it degrades locking performance.
NOTE: If the inner periphery of the friction face shows traces of harsh contact, it is because of the spring tension of each plate, disc and other part. Do not confuse this with abnormal wear.
^ B: Inner periphery and outer periphery protrusions of friction discs, friction plates, and spring plates. Replace a cracked or damaged part.
^ C: Friction and sliding surfaces between pressure rings and friction discs. Grind a dented or scratched part with oil stone and then lap and correct with a compound on a surface plate.
NOTE: If the inner periphery of the friction face shows traces of harsh contact, it is because of the spring tension of each plate, disc and other part. Do not confuse this with abnormal wear.
3. Check the following parts for contact and siding surfaces (D to M) and correct burrs and dents with oil stone.
^ D: Sliding surfaces of side gear and case
^ E: Contacting surfaces of differential case and spring plate
^ F: Contacting surfaces of pressure ring and differential case inner face
^ G: Sliding surfaces of pressure ring hole and side gear
^ H: Protrusions on outer periphery of pressure ring
^ I: Pressure ring inner surface and differential pinion gear spherical surface
^ J: Pressure ring V-groove and pinion shaft V
^ K: Sliding surfaces of pinion shaft and differential pinion gear hole
^ L: Side gear grooves on outer periphery
^ M: Slits in inner periphery of differential
FRICTION PLATE AND FRICTION DISC DISTORSION CHECK
Apply a dial indicator to the friction plate or disc on a surface plate and, turning the friction plate or disc, measure the distortion (flatness).
Limit: 0.08 mm (0.003 inch) [total runout]
FRICTION PLATE, FRICTION DISC, AND SPRING PLATE WEAR CHECK
1. For the purpose of determining wear, measure thickness (A, B) of the friction surface and protrusion at several places and find the difference between the two.
Limit: 0.1 mm (0.004 inch)
2. If the wear exceeds the limit, replace the part with a new one.