General information
1. The driveshaft is a piece of pipe through which torque is transmitted from the gearbox (or, on all-wheel drive versions, from the transfer case) to the differential. U-joints are installed at both ends of the rear driveshaft. On the front driveshaft, the joint is located at the front end (see illustration).
2.1. Details of a typical universal joint
2. The rear propeller shaft has a splined yoke located at the front end. The fork moves horizontally in the extended portion of the transmission or transfer case housing. The presence of a splined connection makes it possible to move the driveshaft relative to the box when the car moves and the suspension elements move. Preventing oil leakage and dirt from entering the box is ensured by the presence of an oil seal at the junction of the fork. If there are signs of transmission oil leakage in front of the propeller shaft, the oil seal must be replaced (see chapter 7A).
3. As a rule, cardan transmission does not require frequent maintenance and repair. The hinges are factory lubricated, which is not replaced during their entire service life. If the technical condition deteriorates, the hinge must be replaced. During the joint replacement procedure, the driveshaft must be removed.
4. Since the driveshaft is a balanced element, it is important to ensure that no dirt builds up on its surface. Whenever the vehicle is lifted for maintenance, clean and perform a maintenance inspection of the shaft. Also ensure that the balance weights are securely attached to their locations. To maintain balance, install the removed propeller shaft without disturbing its original position.
5. Problems in the operation of the cardan transmission are manifested by noise and vibration when the vehicle is moving. Determine the source of the malfunction during a test run. Refer to subsection «Determining the causes of malfunctions» at the beginning of this manual. If signs of malfunction of the cardan transmission elements are found, inspect it.
Inspection
6. Raise the rear of the vehicle and install supports. Chock the front wheels to prevent the vehicle from rolling off the jack stands.
7. While under the car, inspect the driveline. Make sure there are no dents or cracks in the shaft tubes. If these defects are present, the cardan shaft should be replaced.
8. Check for signs of oil leakage at the front and rear ends of the shaft. Traces of leakage in the area where the shaft connects to the gearbox or transfer case indicate failure of the gearbox/transfer case seal (see chapter 7). Signs of oil leakage in the area where the shaft connects to the differential indicate failure of the main gear shaft seal (see subsection 9).
9. While under the car, ask an assistant to rotate the rear wheel so that the driveshafts rotate. Make sure that the universal joints do not make clicks or noise, and do not jam when the shaft rotates.
10. The condition of the hinges can also be assessed without rotating the shaft in the manner described. Grab the parts of the cardan transmission located on the sides of the hinge with your hands and try to rotate them in opposite directions. Movement in the joint during inspection indicates wear.
The condition of the hinges is also assessed when trying to lift the shaft.
11. At the end of the check, make sure that the bolts located at the ends of the driveline are securely tightened.
12. On all-wheel drive models, you should inspect the front driveshaft using the method described above. Inspect the spline fork and surrounding area for signs of oil leakage. Such signs indicate that the plug is failing.
13. Make sure there are no signs of oil leakage in the area where the driveshafts connect to the transfer case, as well as to the front differential. The presence of such signs indicates wear of the seals.
14. Among other things, make sure there is no excessive play of the constant velocity joints (CV joints) front drive shafts. Check for signs of lubricant leakage in the area adjacent to the drive shafts. To do this, you need to inspect the CV joint boots at both ends of the drive shaft. The presence of signs of leakage in the area of the drive shaft flange indicates failure of its oil seal. The presence of grease on the outside of the rubber boot indicates its rupture. The maintenance procedures for these elements are described in the relevant subsections of this chapter.