Front Differential
FRONT DIFFERENTIAL
COMPONENTS
DISASSEMBLY
1. REMOVAL OF THE DIFFERENTIAL CASE ASSEMBLY
CAUTION: Remove the differential case assembly slowly and carefully. Be careful so that the side bearing outer race is not dropped.
NOTE: Keep the right and left side bearings separate so that they are not mixed during reassembly.
2. REMOVAL OF THE SIDE BEARING INNER RACES
Fit the nut on top of the differential case, and then use the special tool (09517-43001) to remove the side bearing inner race.
NOTE: Attach the prongs of the special tool to the inner race of the side bearing through the notched section in the differential case.
3. REMOVAL OF DRIVE GEAR
a. Make the matchmarks to the differential case and the drive gear.
b. Loosen the drive gear attaching bolts in diagonal sequence to remove the drive gear.
4. REMOVAL OF LOCK PIN (FOR CONVENTIONAL DIFFERENTIAL)
5. REMOVAL OF SELF-LOCKING NUT
6. REMOVAL OF DRIVE PINION
a. Make the matchmarks to the drive pinion and companion flange.
CAUTION: Matchmarks should not be made to the contact surfaces of the companion flange and the propeller shaft.
b. Drive out the drive pinion together with the drive pinion spacer and drive pinion front shims.
7. REMOVAL OF DRIVE PINION INNER BEARING INNER RACE
8. REMOVAL OF OIL SEAL/DRIVE PINION OUTER BEARING INNER RACE/DRIVE PINION OUTER BEARING OUTER RACE
9. REMOVAL OF DRIVE PINION INNER BEARING OUTER RACE
INSPECTION
1. Check the companion flange for wear or damage.
2. Check the bearings for wear or discoloration.
3. Check the gear carrier for cracks.
4. Check the drive pinion and drive gear for wear or cracks.
5. Check the side gears, pinion gears and pinion shaft for wear or damage.
6. Check the side gear spline for wear or damage.
7. Check the length of the distance piece.
Standard length: 54.80 - 58.09 mm (2.16 - 2.21 inch)
REASSEMBLY
1. PRESS-FITTING OIL SEAL
2. DRIVE PINION OUTER BEARING OUTER RACE INSTALLATION
CAUTION: When press-fitting the outer race, do not incline it.
3. DRIVE PINION INNER BEARING OUTER RACE INSTALLATION
CAUTION: When press-fitting the outer race, do not incline it.
4. ADJUSTMENT OF PINION HEIGHT
Adjustment the drive pinion height by the following procedure.
1. For assembly of pinion, use drive pinion model(OK993 270 A01), pinion height adjustment gauge body (OK993 270 A09) and gauge block (ht. 28 mm (1.102 inch)).
2. Assemble spacer and inner bearing inner race to pinion model and fix it with O-ring.
NOTE:
^ Use spacer disassembled.
3. Install pinion model assembly to carrier.
4. Assemble outer bearing, companion flange washer, and lock nut.
NOTE:
^ Use washer and lock nut disassembled.
5. Tighten lock nut.
NOTE:
^ Tighten to the extent the companion flange can be screwed by hand.
6. Put pinion height adjusting gauge body at right angle and adjust it to 0.
7. Put pinion height adjusting gauge body and gauge block to the upper side of pinion model.
8. Dial gauge needle should be placed at the lowest part of side bearing.
9. Measure minimum positions of both sides (LH, RH).
10. Add both values and divide it by 2.
11. If the value of the above step 10 is not within specification, use new spacer adding the values to current spacer.
Standard clearance: -0.025 - 0.025 mm (-0.001 - 0.001 inch)
5. Adjustment of drive pinion preload.
1. Install spacer.
2. Push inner bearing in using SST.
NOTE:
^ Keep pressuring until the sudden increase of necessary power.
^ Place file spacer for adjusting pinion height, ensuring exact direction of installation.
3. Install distance piece.
4. Push outer bearing in using SST.
5. Install drive pinion assembly.
6. Install companion flange and tighten lock nut.
Tightening torque: 127 - 284 Nm (13 - 29 kg-m, 94 - 210 ft. lbs.)
NOTE:
^ Do not install oil seal.
7. Turn companion flange by hand so that bearing be put at the right place.
8. Measure preload of drive pinion. If the result is not within specification, use new distance piece and measure again.
Preload: 127 - 176 Nm (13 - 18 kg cm, 94 - 130 ft. lbs.)
9. Remove the lock nut and then install the oil seal.
10. Install the companion flange and tighten lock nut.
Tightening torque: 127 - 284 Nm (13 - 29 kg-m, 94 - 210 ft. lbs.)
6. ADJUSTMENT OF DIFFERENTIAL GEAR BACKLASH
Adjust the differential gear backlash according to the following procedures:
1. Assemble the side gears, side gear spacers, pinion gears, and pinion washers into the differential case.
2. Temporarily install the pinion shaft.
NOTE: Do not install the lock pin yet.
3. Insert a wedge in the side gear and measure the differential gear backlash with a dial indicator on the pinion gear.
NOTE: Measure both pinion gears separately.
Standard value: 0 - 0.1 mm (0 - 0.0039 inch)
Limit: 0.2 mm (0.008 inch)
4. If the differential gear backlash exceeds the limit, adjust the backlash by selecting thicker side gear thrust spacers.
5. Measure the differential gear backlash once again, and confirm that it is within the limit.
NOTE:
^ After adjustment, check that the backlash is within the limit and the differential gear rotates smoothly
^ When adjustment is impossible, replace the side gear and the pinion gear as a set.
7. INSTALLATION OF THE LOCK PIN
1. Align the pinion shaft lock pin hole with the differential case lock pin hole, and drive in the lock pin.
2. Fix the lock pin in place by staking two points around the lock pin hole with a punch.
8. INSTALLATION OF THE DRIVE GEAR
1. Clean the drive gear attaching bolts.
2. Remove the adhesive on the threaded holes of the drive gear use a tap (M10 x 1.25), and then clean the threaded holes with compressed air.
3. Apply the specified adhesive to the threaded holes of the drive gear.
Specified adhesive: LOCTITE #262 or equivalent
4. Install the drive gear in the differential case with the matchmarks properly aligned. Tighten the bolts to the specified torque in a diagonal sequence.
9. PRESS THE SIDE BEARING INNER RACE
10. Attach actuator at differential case RH side as figure
CAUTION: Take heed of actuator direction.
11. ADJUSTMENT OF FINAL DRIVE GEAR BACKLASH
Adjust the final drive gear backlash according to the following procedures:
1. Install side bearing spacers which are thinner than those removed, to the side bearing outer races, and then mount the differential case assembly into the gear carrier.
NOTE: Select side bearing spacers with the same thickness for both the drive pinion side and the drive gear side.
2. Push the differential case to one side, and measure the clearance between the gear carrier and the side bearing with a feeler gauge.
3. Select two pairs of spacers which correspond to the value calculated according to the expression in the illustration. Install one pair each to the drive pinion side and the drive gear side.
4. Install the side bearing spacers and differential case assembly, as shown in the illustration, to the gear carrier.
5. Tap the side bearing spacers with a brass bar to fit them to the side bearing outer race.
6. Align the matchmarks on the gear carrier and the bearing cap and tighten the bearing cap.
7. With the drive pinion locked in place, measure the final drive gear backlash with a dial indicator on the drive gear.
NOTE: Measure at four points or more on the circumference of the drive gear.
Standard value: 0.09 - 0.11 mm (0.0035 - 0.0043 inch)
8. Change the side bearing spacers as illustrated and then adjust the final drive gear backlash between the drive gear and the drive pinion.
NOTE: When increasing the number of side bearing spacers, use the same number for each and as few as possible.
9. Check the drive gear and drive pinion for tooth contact. If poor contact is evident, adjust again.
10. Measure the drive gear runout at the shoulder on the reverse side of the drive gear.
Limit: 0.05 mm (0.002 inch)
11. If the drive gear runout exceeds the limit, reinstall by changing the position of the drive gear and differential case, and remeasure.