Contents: Replacing the rear oil seal without…↓ Removal the gearbox ↓ Installing the gearbox ↓ Checking the gearbox ↓
Gearbox assembly. 1 - gasket; 2 - brake system pipes; 3 - steering damper; 4 - transverse steering rod; 5 - gearbox; 6 - front propeller shaft; 7 - gasket; 8 - cotter pin; 9 - gasket; 10 - steering knuckle axis; 11 - axle shaft assembly.
Reducer. 1 - locking plates; 2 - bearing caps; 3 - gearbox charter; 4 - outer race of the front bearing; 5 - front bearing; 6 - oil deflector ring; 7 - oil seal; 8 - anther; 9 - drive gear flange; 10 - washer; 11 - driven gear; 12 - leading gear; 13 - washer; 14 - rear bearing; 15 - outer race of the rear bearing; 16 - spacer sleeve; 17 - locking plate; 18 - differential cup; 19 - differential cup bearing; 20 - outer race of differential cup bearing; 21 - differential cup bearing adjusting nut.
Replacing the rear oil seal without removing the gearbox from the vehicle
1. Removing the front propeller shaft.
a) Apply marks to the front propeller shaft flange and the final drive pinion flange.
b) Remove the four bolts and nuts and disconnect the front propeller shaft.
2. Removing the flange of the main gear drive pinion.
a) Using a chisel and hammer, release the calked portion of the flange mounting nut.
b) Holding the flange with a special tool, remove the nut and plate washer.
c) Using a special tool, remove the connecting flange.
3. Using a special tool, remove the oil seal, then remove the oil deflector ring.
4. Using a special tool, remove the rear pinion bearing.
5. Remove the bearing spacer sleeve.
6. Install the new bearing spacer sleeve.
7. Install the rear bearing.
8. Installing the oil deflector ring and new seal.
a) Install the oil deflector ring as shown in the figure.
b) Using the special tool, install the new oil seal as shown in the figure.
The depth of pressing the seal is 1.0 mm
c) Apply grease to the seal lip.
9. Installing the flange of the main gear drive pinion.
a) Using a special tool, install the flange onto the drive gear.
b) Install the flat washer onto the flange.
c) Apply a small amount of transmission oil to the threads of the new flange mounting nut.
d) Hold the flange and tighten the nut.
Tightening torque - 196 Nm
10. Checking the preload of the drive gear bearings.
a) Using a torque wrench, measure the preload.
Preload (initial):
- new bearing - 1.9 - 2.5 Nm
- old bearing - 0.9-1.3 Nm
b) If the preload is greater than the specified value, replace the spacer sleeve.
c) If the preload is less than the specified value, re-tighten the nut with a torque of 13 N·m greater than the nominal value (196 N·m) until the specified preload is reached.
d) If the maximum tightening torque is exceeded when tightening the nut, it is necessary to replace the bearing spacer sleeve and repeat the procedure.
Maximum tightening torque: 343 Nm
Caution: Do not loosen the nut to reduce the preload.
11. Pin the drive gear nut.
12. Align the marks and connect the flange of the main gear pinion with the flange of the cardan shaft. Secure the flanges with bolts, spring washers and nuts. Tighten the bolts and nuts.
Tightening torque - 74 Nm
13. Check the oil level in the gearbox housing. Add oil if necessary.
Removal the gearbox
1. Unscrew the drain plug and drain the oil from the gearbox housing.
2. Remove the axle shafts as an assembly from the front axle housing.
3. Removing the transverse steering rod.
a) Using a special tool, disconnect the transverse rod from the lower arm of the steering knuckle.
b) Unscrew the two bolts securing the steering damper bracket.
4. Disconnect the front propeller shaft.
5. Removing the brake system pipes.
a) Disconnect the tube from the frame side and remove the clamp.
b) Unscrew the clamp mounting bolts and remove the tee assembly with the hose and tubes.
6. Loosen the bolts and remove the gearbox housing.
Caution: Be careful not to damage the mounting surfaces.
Installing the gearbox
1. Install a new gasket.
2. Install the gearbox housing onto the front axle and tighten the two nuts and eight mounting bolts.
Tightening torque: 27 Nm
3. Installing brake system pipes.
a) Install the tee assembly with the hose and tubes. Tighten the clamp mounting bolts.
b) Connect the tube from the frame side and install the clamp.
4. Connect the front propeller shaft.
5. Installing the transverse steering rod,
a) Install the steering damper bracket and tighten the two mounting bolts.
Tightening torque: 19 Nm
b) Connect the tie rod to the lower arm of the steering knuckle. Tighten the castle nut and install the cotter pin.
Tightening torque - 91 Nm
6. Install the axle shafts as an assembly.
7. Install the drain plug.
8. Fill the gearbox housing with transmission oil.
Checking the gearbox
1. Checking the runout of the main gear drive flange.
a) Using a dial indicator, measure the axial runout of the flange.
Maximum axial runout - 0.10 mm
b) Using a dial indicator, measure the radial runout of the flange.
Maximum radial runout - 0.10 mm
2. Checking the runout of the driven gear of the main transmission.
a) Measure the runout of the driven gear.
Maximum runout - 0.10 mm
b) If the runout exceeds the maximum value, replace the final drive driven gear.
3. Checking the lateral clearance between the teeth of the driven and driving gears.
a) Place the indicator on the tooth surface at an angle of 90°.
b) Holding the flange of the drive gear, measure the lateral clearance in the engagement of the driven and drive gears.
Lateral clearance between the teeth of the driven and driving gears is 0.13-0.18 mm
Note: Take measurements at three or more points on the periphery of the driven gear.
c) If the side clearance is not within the specified range, adjust the side bearing preload or repair if necessary.
4. Checking the preload of the drive gear.
Measure the preload provided by the clearance between the teeth of the driven and driving gears.
Preload (initial) - 0.9 -1.3 Nm
5. Checking the overall preload.
a) Measure the total preload.
Total preload: Add 0.4-0.6 N·m to the preload value of the drive gear.
b) If necessary, disassemble and check the differential.
6. Checking the lateral clearance in the engagement of the axle gear.
a) Measure the side clearance between the teeth on the axle gear by pressing one of the satellites against the differential cup.
Permissible gap - 0.05 - 0.20 mm
b) If the clearance value is outside the permissible limits, thrust washers of the appropriate size should be installed.
Thrust washers thickness - 1.6; 1,7; 1.8 mm
7. Checking the contact patch between the teeth of the driving and driven gears.
a) Apply red paint to 3-4 teeth of the driven gear in three different places.
b) While holding the drive gear flange, turn the driven gear in both directions.
c) Check the shape of the contact patch between the gear teeth.
d) If the pinion gear is too far from the center of the driven gear, increase the thickness of the adjusting shim to bring the driven and pinion gears closer together, or move the driven gear away from the pinion gear to adjust the backlash.
Thickness of adjusting washers - 1.70 - 2.33 mm (with a step of 0.03 mm)
d) If the pinion gear is too close to the center of the driven gear, reduce the thickness of the adjusting shim to move the driven gear away from the pinion gear, or move the driven gear closer to the pinion gear to adjust the backlash.
8. Checking the differential cup runout.
Using a dial indicator, measure the differential cup runout.
Maximum runout - 0.07 mm
