Part 1

FRONT FINAL DRIVE


Disassembly and Assembly


COMPONENTS











ASSEMBLY INSPECTION AND ADJUSTMENT
- Drain the differential gear oil before inspection and adjustment. Changing Differential Gear Oil Checking Differential Gear Oil.
- Remove and install the carrier cover as necessary for inspection and adjustment. Front Final Drive R180A.

Total Preload Torque
1. Install the differential side shaft if necessary. Side Oil Seal.

CAUTION:
The differential side shaft must be installed in order to measure total preload torque.
2. Rotate the drive pinion back and forth 2 to 3 times to check for unusual noise and rotation malfunction.
3. Rotate the drive pinion at least 20 times to check for smooth operation of the bearings.





4. Measure total preload torque using Tool.






NOTE:
Total preload torque = Drive pinion bearing preload torque +
Side bearing preload torque
- If the measured value is out of the specification, check and adjust each part. Adjust the drive pinion bearing preload torque first, then adjust the side bearing preload torque.






CAUTION:
Select a side bearing adjusting washer for right and left individually.

Drive Gear Runout





1. Fit a dial indicator to the drive gear back face.
2. Rotate the drive gear to measure runout.

Runout limit: Refer to Inspection And Adjustment

- If the runout is outside of the limit, check the condition of the drive gear assembly. Foreign material may be caught between the drive gear and differential case, or the differential case or drive gear may be deformed.

CAUTION:
Replace drive gear and drive pinion as a set.

Tooth Contact





1. Apply red lead to the drive gear.

NOTE:
Apply red lead to both faces of three to four gears, at four locations evenly spaced on the drive gear.





2. Rotate the drive gear back and forth several times. Then check for correct drive pinion to drive gear tooth contact as shown.

CAUTION:
Check tooth contact on drive side and reverse side.





- If the tooth contact is improperly adjusted, adjust the drive pinion height (dimension X).





- If the tooth contact is near the face (face contact), or near the heel (heel contact), use a thicker drive pinion height adjusting washer to move drive pinion closer to the drive gear. Disassembly And Assembly.





- If the tooth contact is near the flank (flank contact), or near the toe (toe contact), use a thinner drive pinion height adjusting washer to move the drive pinion farther from the drive gear. Inspection And Adjustment.

Backlash





1. Fit a dial indicator to the drive gear face to measure the backlash.

Backlash: Refer to Inspection And Adjustment

- If the backlash is outside of the specification, change the thickness of the side bearing adjusting washers.






CAUTION:
Do not change the total thickness of side bearing adjusting washers as it will change the side bearing preload torque.

Companion Flange Runout





1. Rotate companion flange and check for runout on the companion flange face (inner side of the bolt holes) and companion flange inner side (socket diameter) using suitable tool.

Runout limit: Refer to Inspection And Adjustment

2. If the runout is outside the runout limit, follow the procedure below to adjust.
Rotate the companion flange on the drive pinion by 90�, 180�
a.
and 270� while checking for the position where the runout is minimum.
b. If the runout is still outside of the runout limit after the companion flange has been rotated on the drive pinion, possible cause could be an assembly malfunction of drive pinion and drive pinion bearing or a malfunctioning drive pinion bearing.
c. If the runout is still outside of the runout limit after repair of the assembly of drive pinion and drive pinion bearing or drive pinion bearing, replace the companion flange.

DISASSEMBLY

Differential side shaft
1. Drain the differential gear oil if necessary.





2. Remove the carrier cover bolts and separate the carrier cover from the gear carrier using Tool.

Tool number : KV10111100 (J-37228)


CAUTION:
- Do not damage the mating surface.
- Do not insert flat-bladed screwdriver, this will damage the mating surface.





3. Remove side oil seal.

CAUTION:
Do not damage gear carrier.





4. Remove snap ring (hole side) using suitable tool.





5. Remove differential side shaft assembly out of gear carrier using suitable tool.

NOTE:
Tap on differential side shaft assembly from side gear side.
6. Remove snap ring (differential side shaft side).





7. Press differential side shaft out of differential side shaft bearing.

CAUTION:
Do not drop differential side shaft.

Differential Assembly
1. Remove differential side shaft assembly. Side Oil Seal.
2. Remove side seal from gear carrier using suitable tool.





3. For proper reinstallation, paint matching marks on one side of the side bearing cap and gear carrier.

CAUTION:
- For matching marks, use paint. Do not damage side bearing cap or gear carrier.
- Side bearing caps are line-board during manufacture. The matching marks are used to reinstall them in their original positions.





4. Remove the side bearing caps.





5. Lift the differential case assembly out of the gear carrier.

CAUTION:
- Keep side bearing outer races together with side bearing inner races. Do not mix them up.
- Keep side bearing adjusting washers together with side bearings.
6. Remove housing spacer.





7. Remove side bearing inner race using Tools as shown.






CAUTION:
- Do not remove side bearing inner race unless it is being replaced.
- Place copper plates between the vise and the side bearing inner race and drive gear to prevent damage.





- Keep side bearing outer races together with side bearing inner races. Do not mix them up.





8. For proper reinstallation, paint matching marks on the differential case and drive gear.

CAUTION:
Use paint for matching marks. Do not damage differential case or drive gear.
9. Remove the drive gear bolts.
10. Tap the drive gear off the differential case using suitable tool.

CAUTION:
Tap evenly all around to keep drive gear from bending.





11. Remove the lock pin of the pinion mate shaft from the drive gear side using suitable tool.





12. Remove the pinion mate shaft.





13. Turn the pinion mate gear, then remove the pinion mate gear, pinion mate thrust washer, side gear and side gear thrust washer from the differential case.

Drive Pinion Assembly
1. Remove the differential assembly. Disassembly And Assembly.





2. Remove the drive pinion lock nut using suitable tool.
3. Put matching marks on the companion flange and drive pinion using paint.

CAUTION:
Use paint to make the matching marks. Do not damage the companion flange or drive pinion.





4. Remove the companion flange using suitable tool.





5. Press the drive pinion assembly (with rear inner bearing race and collapsible spacer) out of the gear carrier.

CAUTION:
Do not drop drive pinion assembly.





6. Remove the drive pinion rear bearing inner race and drive pinion height adjusting washer using Tool.

Tool number : ST30031000 (J-22912-01)






7. Remove the front oil seal using suitable tool.

CAUTION:
Do not damage gear carrier.
8. Remove the drive pinion front bearing inner race.





9. Remove the drive pinion front and rear bearing outer races by tapping them uniformly using suitable tool.

CAUTION:
Do not damage gear carrier.

INSPECTION AFTER DISASSEMBLY
Clean the disassembled parts. Then inspect the parts for wear or damage. If wear or damage are found, follow the measures below.

Drive Pinion and Drive Gear
- If the drive pinion and drive gear teeth do not mesh or line-up correctly, determine the cause and adjust, repair, or replace as necessary.
- If the drive pinion or drive gear are worn, cracked, damaged, pitted or chipped (by friction) noticeably, replace with new drive pinion and drive gear.
- Drive pinion and drive gear are supplied in matched sets only. Matching numbers on both drive pinion and drive gear are etched for verification. If a new drive pinion and drive gear set are being used, verify the numbers of each drive pinion and drive gear before proceeding with assembly.

Bearing
- If bearings are chipped (by friction), pitted, worn, rusted, scratched, or unusual noise is coming from bearing, replace with new bearing assembly (as a new set).
- Bearing must be replaced with a new one whenever disassembled.

Side Gear and Pinion Mate Gear
- If any cracks or damage are found on the surface of the teeth, replace with new one.
- If any worn or chipped marks are found on the side of the side gear and pinion mate gear which contact the thrust washer, replace with new one.
- Replace both side gear and pinion mate gear as a set when replacing side gear or pinion mate gear.

Side Gear Thrust Washer and Pinion Mate Thrust Washer
- If any chips (by friction), damage, or unusual wear are found, replace with new one.

Gear Carrier
- If any wear or cracks are found on the contact sides of gear carrier, replace with new one.

Companion Flange
- If any chips (about 0.1mm, 0.004 in) or other damage on the companion flange surface which contacts the front oil seal lips are found, replace with new one.

ADJUSTING AND SELECTING WASHERS

Side Gear Back Clearance
- Assemble the differential parts if they are disassembled. Disassembly And Assembly.





1. Place the differential case straight up so that the side gear to be measured is upward.





2. Using feeler gauges, measure the clearance between the side gear back and differential case at three different points, while rotating the side gear. Average the three readings to calculate the clearance. (Measure the clearance of the other side as well.)

Side gear back clearance: Refer to Inspection And Adjustment

- If the side gear back clearance is outside of the specification, use a thicker or thinner side gear thrust washer to adjust. Inspection And Adjustment.






CAUTION:
- Insert feeler gauges with the same thickness on both sides to prevent side gear from tilting.
- Each gear should rotate smoothly without excessive resistance during differential motion.
- Select a side gear thrust washer for right and left individually.

NOTE:
Side gear back clearance is clearance between side gear and differential case for adjusting side gear backlash.

Drive Pinion Height
1. Make sure all parts are clean and that the bearings are well lubricated.





2. Assemble the drive pinion bearings onto the Tool.

Tool number : - (J-34309)





- Drive pinion front bearing; make sure the J-34309-3 drive pinion front bearing seat is secured tightly against the J-34309-2 gauge anvil. Then turn the J-34309-7 drive pinion front bearing pilot to secure the drive pinon front bearing in its proper position.
- Drive pinion rear bearing; the J-34309-8 drive pinion rear bearing pilot is used to center the drive pinion rear bearing only. The J-34309-4 drive pinion rear bearing locking seat is used to lock the drive pinion rear bearing to the assembly.
- Installation of J-34309-9 and J-34309-16; place a suitable 2.5 mm (0.098 in) thick plain washer between J-34309-9 and
J-34309-16. Both surfaces of J-34309-9 and J-34309-16 must be parallel with a clearance of 2.5 mm (0.098 in).





3. Install the drive pinion rear bearing inner race into the gear carrier. Then insert the drive pinion height adjusting washer selector tool, J-34309-1, gauge screw assembly.





4. Assemble the drive pinion front bearing inner race and the J-34309-2 gauge anvil. Assemble them together with the J-34309-1 gauge screw in the gear carrier. Make sure that the drive pinion height gauge plate, J-34309-16, will turn a full 360�. Tighten the two sections together by hand.





5. Turn the assembly several times to seat the drive pinon bearings.