35 The appearance of transmission oil drips in front of the propeller shaft
Failure of the gearbox or transfer case oil seal (chapter 7). Also inspect the splines of the flange yoke of the propeller shaft for burrs and burrs, since if these defects are present, the seal will be damaged. Remove defects using fine-grained sandpaper or an abrasive stone.
36 When transferring load to the gearbox, clicking and knocking noises are heard (immediately after switching on the gear)
1. Loosening or disconnecting a rear suspension element. Check the tightness of the fasteners and the reliability of the connecting sleeves (see chapter 10).
2. Loosening the propeller shaft bolts. Check the tightness of the fasteners and bring it into compliance with the standard.
3. Worn or damaged universal joint bearings. Inspect for signs of wear (chapter 8).
37 When the speed increases, a metallic grinding noise appears
Manifestation of wear on the cardan joint bearings. Inspect for signs of wear (chapter 8).
38 Vibration detected
Note: Before deciding whether the driveshaft has failed, ensure that the wheels are in dynamic balance, then perform the following check.
1. Install a tachometer in the cabin to monitor engine speed when the car is moving. Drive the car, monitoring the engine speed using the tachometer. Determine the rotation speed at which vibration is most pronounced. When driving the engine, maintain the set speed in all gears.
2. If there is vibration at certain engine speeds (regardless of the selected gear) failure of the driveshaft can be excluded, since in this case its rotation frequency changes.
3. If vibration decreases or disappears when shifting gears and maintaining the specified speed, one or more of the following reasons should be assumed.
4. Misalignment or bending of the driveshaft. Check and replace if necessary (chapter 8).
5. Tar or road dirt sticking to the shaft. Clean and inspect the shaft.
6. Wear of universal joint bearings. Remove and inspect the hinge (chapter 8).
7. Unbalance of the driveshaft and/or connecting flange. Make sure there are balancing weights on the shaft. Remove the driveshaft (chapter 8) and reinstall it by rotating it 180°. If the vibration does not disappear after this, have the shaft balanced at an appropriately qualified station.