Drive shafts (4WD models) — general information and inspection (Chevrolet Trailblazer 1)

1. Torque from the front differential/axle is transmitted to the wheels via a pair of drive shafts. The inner end of the right drive shaft is splined to the right differential axle gear. On the inner end of the left drive shaft is a short splined projection that connects to the left side gear. The outer ends of both drive shafts are splined for connection to the hubs/wheel bearings. The shafts are fastened to the hubs with large nuts.

2. At the inner ends of the drive shafts there are constant velocity joints (CV joints), which have axial and radial mobility. Each inner CV joint consists of a bearing with a tripod and a housing in which the joint can move in the axial direction when the drive shafts move together with the wheels in the vertical plane.

3. At the outer ends of the drive shafts there are CV joints with ball bearings. These joints have radial rather than axial mobility. They contain bearings with six balls that roll between the inner race and the joint housing.

4. Periodically, it is necessary to inspect the hinge covers for damage and signs of grease leakage. A torn cover must be replaced immediately, otherwise the hinge will be damaged. If it is necessary to replace one or both boots, the drive shaft must be removed (see subsection 12).

5. If damage to the cover is detected, it is necessary to disassemble and clean the hinge (see subsection 13). If damage to one of the joint elements is detected, the entire drive shaft must be replaced.

6. The most common symptom of joint failure, along with signs of grease leakage, is the presence of clicking sounds when turning, as well as a rumble when accelerating from coasting and vibration at high speeds. To determine the degree of wear of the joint and the protrusion of the drive shaft, it is necessary to grasp the shaft and try to turn it from side to side, while holding the CV joint housing. The relative movement displays the degree of wear of the splines or joint. You also need to make sure that the shaft is not cracked, dented or bent.

[The article is reprinted from the website ChevyMan.ru]