GM Full-Size Trucks 1980-1987 Repair Guide



Tubular driveshafts are used on all models, incorporating needle bearing U-joints. An internally splined sleeve at the forward end compensates for variation in distance between the rear axle and the transmission.

The number of driveshafts used is determined by the length of the wheelbase. On trucks that use two driveshafts there is a center support incorporating a rubber cushioned ball bearing mounted in a bracket attached to the frame crossmember. The ball bearing is permanently sealed and lubricated. 4-WD models use a front driveshaft with a constant velocity joint.

Extended lift U-joints have been incorporated on most models and can be identified by the absence of a lubrication fitting.