Assembly
DIFFERENTIAL CARRIER ASSEMBLYASSEMBLY
Assembly Steps 1-28:
Required Special Tools:
^ MB990326: Preload Socket
^ MB990392: Cylinder Gauge
^ MB990685: Torque Wrench
^ MB990727: Oil Seal Installer
^ MB990728: Bearing Installer
^ MB990836: Drive Pinion Gauge Assembly
^ MB990850: End Yoke Holder
^ MB990932: Installer Adapter
^ MB990936: Installer Adapter
^ MB990938: Installer Bar
^ MB991115: Oil Seal Installer
LUBRICATION AND ADHESIVE POINTS
ASSEMBLY SERVICE POINTS
]]A[[ OIL SEAL PRESS-FITTING
Use special tools MB990938 and MB991115 to press-fit a new oil seal.
]]B[[ DRIVE PINION REAR BEARING OUTER RACE PRESS-FITTING
Use special tools MB990938 and M B990935 to press-fit the drive pinion rear bearing outer race.
]]C[[ DRIVE PINION FRONT BEARING OUTER RACE PRESS-FITTING
Use special tools MB990938 and MB990932 to press-fit the drive pinion front bearing outer race.
]]D[[ DRIVE PINION HEIGHT ADJUSTMENT
Adjust the drive pinion height by the following procedures:
1. Apply multipurpose grease to the washer of special tool MB990836.
CAUTION:
There should be no gear oil adhered to the bearing.
2. Install special tool MB990836, drive pinion front and rear bearing inner races to the differential carrier as shown in the illustration.
3. Tighten the nut of special tool MB990836 a little at a time, while measuring the turning torque of the drive pinion by using special tools MB990326 and MB990685. Then confirm that the turning torque (without the drive pinion oil seal) is at the standard value.
Standard value:
NOTE: Because special tool MB990326 cannot be turned one turn, turn it several times within the range that it can be turned; then, after fitting to the bearing, measure the turning torque.
4. Clean the side bearing seat of the differential carrier and bearing caps.
5. Place special tools MB990392 and MB990836 in the side bearing seat of the differential carrier, and position the notch as shown in the illustration. Then install the bearing caps.
6. Use a feeler gauge to measure the clearance (A) between special tools.
7. Remove the bearing caps and special tools.
8. Use a micrometer to measure the shown dimensions (B, C) of special tools.
9. Install the bearing cap, and then use a cylinder gauge to measure the inside diameter (D) of the bearing cap.
10. Calculate thickness (F) of the required drive pinion rear shim by the following formula. Select a shim which most closely matches this thickness.
F = A + B + C - 1/2D - 86.00 mm (3.386 inches)
11. Fit the selected drive pinion rear shim(s) to the drive pinion, and press-fit the drive pinion rear bearing inner race by using special tool MB990728.
]]E[[ DRIVE PINION TURNING TORQUE ADJUSTMENT/OIL SEAL INSTALLATION
Adjust the drive pinion turning torque by the following procedures:
1. Insert the drive pinion into the differential carrier, and then install the following parts in sequence from the carrier rear side: drive pinion spacer, drive pinion front shim, drive pinion front bearing inner race and companion flange.
NOTE: Do not install the oil seal.
2. Tighten the companion flange self-locking nut to the specified torque while holding the companion flange with special tool MB990850.
Tightening torque: 190 ± 30 Nm (140 ± 22 ft-lb)
CAUTION:
There should be no gear oil adhered to the bearing.
3. Use special tools MB990326 and MB990685 to measure the drive pinion turning torque (without the drive pinion oil seal).
Standard value:
4. If the drive pinion turning torque is not within the standard value, adjust the turning torque by replacing the drive pinion front shim(s) or the drive pinion spacer.
NOTE: When selecting the drive pinion front shims, if the number of shims is large, reduce the number of shims to a minimum by selecting the drive pinion spacers.
Select the drive pinion spacer from the following two types.
5. Remove the companion flange and drive pinion again. Then insert the drive pinion front bearing inner race into the differential carrier. Use special tool MB990727 to press-fit the drive pinion oil seal.
6. Install the drive pinion assembly and companion flange with the mating marks properly aligned. Tighten the companion flange self-locking nut to the specified torque while holding the companion flange with special tool MB990850.
Tightening torque: 190 ± 30 Nm (140 ± 22 ft-lb)
7. Use special tools to measure the drive pinion turning torque (with drive pinion oil seal) to verify that the drive pinion turning torque complies with the standard value.
Standard value:
8. If the turning torque is not within the standard value, check the tightening torque of the companion flange self-locking nut, and the installation of the oil seal.
]]F[[ DRIVE GEAR INSTALLATION
1. Clean the drive gear attaching bolts.
2. Remove the adhesive adhered to the threaded holes of the drive gear by turning the tap (M10 x 1.25). Clean the threaded holes by applying compressed air.
3. Apply the specified sealant to the threaded holes of the drive gear.
Specified sealant: 3M TM AAD Part No.8730, 8731 or equivalent
4. Install the drive gear onto the limited slip differential case with the mating marks properly aligned. Tighten the drive gear attaching bolts to the specified torque in a diagonal sequence.
Tightening torque: 84 ± 4 Nm (62 ± 2 ft-lb)
]]G[[ DIFFERENTIAL SIDE BEARING INNER RACE INSTALLATION
Use special tool MB990728 to press-fit the differential side bearing inner races into the differential case.
]]H[[ FINAL DRIVE GEAR BACKLASH ADJUSTMENT
Adjust the final drive gear backlash by the following procedure:
1. Assemble the differential case with the side bearing outer race to the differential carrier.
2. Press the differential case to one side to measure the clearance of the side bearing outer race and the differential carrier.
3. Select two pairs of side bearing spacers. Determine the thickness by adding 1/2 of the clearance to the pre-load 0.05 mm (0.002 inch).
4. Assemble the selected side bearing spacers to each side.
5. Measure the final drive gear backlash at four points or more on the circumference of the drive gear.
Standard value: 0.11 - 0.16 mm (0.004 - 0.006 inch)
6. If the backlash is not within the standard value, move the side bearing spacer as shown in the illustration to adjust the backlash.
NOTE: The increment of side bearing spacer must be the same as the decreased amount.
7. Inspect the tooth condition at the final drive gear and replace if required.
8. Measure the drive gear runout.
Limit: 0.05 mm (0.002 inch)
9. If drive gear runout exceeds the limit, remove the differential case and then the drive gears, moving them to different positions and reinstall them.
10. If adjustment is not possible, replace the differential case or drive gear and drive pinion as a set.
DISASSEMBLY AND ASSEMBLY
Disassembly Steps 1-20:
DISASSEMBLY SERVICE POINT
[[A]] 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.
Specified gear oil: MITSUBISHI Genuine DIA QUEEN LSD gear oil
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 the following special tools to check for differential torque.
^ Base (MB990989)
^ Tool A (MB990990)
Standard value:
[When a new clutch plate is used]: 2.1 - 2.9 Nm (18.6 - 25.7 in-lb)
[When the current clutch plate is reused]: 2.1 - 2.9 Nm (18.6 - 25.7 in-lb)
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 DISTORTION 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)
FRICTION PLATE AND FRICTION DISC 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.