The cardan gear used on the car consists of two shafts - an intermediate 2 (Fig. Cardan gear) and a rear axle 7, as well as an intermediate support 5 with a bearing 22
The cardan shafts are connected to each other by a cardan joint.
Maximum allowable dimensions, mm:
- radial backlash of spider bearings 0.1
- PTO shaft runout 0.3
- drive gear flange runout 0.15
- gearbox output shaft runout 0.15
Removing the Driveline
Mount the vehicle on a pit or lift.
Clean the threaded connections of the driveline mount from dust and dirt.
Unscrew two nuts 1 securing the intermediate support bracket to the body, two bolts 2 securing the bracket to the intermediate support 4 and remove the bracket 3.
Unscrew the four bolts securing the driveline to the flange of the rear axle drive gear, having previously marked the relative position of the flanges.
Remove the driveline.
If it is difficult to detach the flange of the rear propeller shaft from the flange of the rear axle drive gear, it is allowed to apply light blows with a soft metal hammer on the flange of the rear propeller shaft (but in no case on the cardan bearing).
To prevent oil from leaking out of the gearbox, insert a plug into the extension of the rear gearbox housing.
Disassembly of the driveline
Mark the relative position of the shafts, the sliding fork and the flange of the rear driveshaft.
Unbend the edges of the lock washer 2 and loosen the bolt 1 so that you can remove the U-shaped plate 3.
Disconnect cardan shafts. Press intermediate support 1 complete with shaft bearing.
Clean the universal joint from dust and dirt.
Mark the relative position of the universal joint forks.
Remove the circlips of the spider bearings.
Press out two opposite cross-bearings from the lugs at the same time (one bearing is pressed out and the other inside the fork) and remove them.
When pressing out, make sure that the tool used as a mandrel does not damage the grease fitting screwed into the cross.
Similarly, press out the second pair of bearings of the cross, remove the bearings, sealing collars, mud deflectors and cross.
Inspection and defect detection of cardan gear parts
Clean the components and parts of the driveline from dust, dirt and oil.
Cardan shafts must not show signs of deformation.
Breakage of the bearing needles, traces of needles being pressed into the bearing housing and into the trunnion of the cross are not allowed.
The oil passages of the spider must be clean.
The sealing cuff must be resilient and elastic, must not have cracks or breaks.
Traces of oil leakage through the sealing collar during a maintenance operation to add grease to the bearing cavities are not a defect.
The grease nipple must provide unhindered access of oil to the bearings of the spider when adding lubricant during operation.
It is not allowed to leak oil from the bearing cavities through the grease fitting.
The bearing of the intermediate support should rotate easily and not have chipping, pitting, shells, tinting on the rolling surfaces.
The rubber part of the intermediate support must be elastic and free from cracks and breaks. Vulcanized parts should not show signs of separation.
Fasteners must not have thread defects.
If during inspection it is found that the components and parts do not meet the above requirements, then they before replace.
Before installing new needle bearings, the glasses and needles must be cleaned of conservation grease.
This operation is carried out for each bearing separately, eliminating the possibility of mixing the needles of different bearings.
Pour gear oil up to half the volume of the glass and insert the needle into the glass.
Clean the new cross from conservation grease (including channels) and screw a grease fitting into the threaded hole.
Put sealing collars 1 and dirt deflectors 2 on the trunnions of the cross.
Insert the assembled crosspiece inside the universal joint so that, after assembling the universal joint, the grease fittings of each universal joint are located on one side.
Insert the bearing with needles into the eye of the fork and insert the trunnion of the cross into the bearing.
Pre-press the installed bearing into the eye, while holding the inserted cross from falling out.
Insert the second bearing into the opposite eye, aligning the bearing hole and the trunnion of the cross, and press it into the eye, while turning the cross on the bearings.
Finally press in the first bearing so that the grooves for the circlips are located at an equal distance "a" relative to the inner ends of the fork.
Insert the retaining rings into the grooves of the bearings, orienting their antennae inside the fork.
Insert the free trunnions of the cross into another fork in the same way.
Check the ease of movement of the fork in different planes.
The driveline assembly is carried out in the reverse order of disassembly, in accordance with the previously made marks.
Installation of the driveline is carried out in the reverse order of removal, in accordance with the previously made marks.
Tighten the bolts securing the driveline flange to the final drive gear flange to 27–30 Nm (2.7–3.0 kgf m).
Nominal and maximum allowable dimensions and fit of cardan gear mating parts
|30 –0.009||Sliding Fork||30 –0.010
under the bearing
on the cross
Possible cardan failures
Gimbal vibration when driving
Deformation of the propeller shaft tube - Replace the propeller shaft tube or have it repaired in specialized workshops with mandatory dynamic balancing
Loosening the fastening of the rear driveshaft to the rear axle - Tighten the screw connections
Balancing plate detached from the shaft tube - Replace the cardan shaft tube or have it repaired in specialized workshops with mandatory dynamic balancing
Increased play of the cross in the bearings of the universal joint - Replace the bearings and crosses of the universal joint
Increased runout of the rear axle drive gear flange - Replace the flange
Increased runout of the sliding fork installed in the gearbox - Eliminate the cause of the runout of the output shaft. Replace the gearbox extension due to wear of the steel-babbitt bushings
Intermediate bearing defective - Replace bearing
Loose fastening of the intermediate support to the bracket or the bracket to the underbody - Tighten the screw connections