GM 19201890 Shaft Asm,Front & Rear Propeller

A driveshaft is a tube or pair of tubes that transmits power between the transmission or transfer case on 4WD models and the differential. It is equipped with universal joints at either end and in the center for two-piece driveshafts. On 2WD models, the driveshaft has a splined yoke at the front that allows it to slide back and forth within the transmission, with an oil seal to prevent fluid leakage and dirt entry. For 4WD models, the driveshaft may have a splined yoke or companion flange at the transfer case end, and two-piece driveshafts usually have a slip joint at the front of the rear section. Center bearings support the driveline in two-piece driveshafts, mounted in a rubber cushion on a frame crossmember. The driveshaft requires minimal service, with the universal joints being lubricated for life and replaced if problems arise. It is important to keep the driveshaft clean and inspect it for damage, ensuring the small weights used for balancing are in place and securely attached. Any noise or vibration while driving may indicate a problem with the driveshaft, which can be verified through a road test.

To remove the rear driveshaft, start by disconnecting the negative cable from the battery. Then, raise the vehicle and support it securely on jackstands. Make marks on the driveshaft and the differential flange to ensure proper reinstallation. Remove the rear universal joint bolts and straps, and if applicable, remove the bolts, nuts, and washers from the companion flange. If the vehicle has a two-piece driveshaft, remove the bolts, nuts, and washers from the center support bearing bracket. Lower the rear of the driveshaft and slide the front out of the transmission or transfer case. If there is a splined yoke, cover it with a plastic bag to prevent fluid loss. If replacing the center support bearing, unscrew the collar, separate the driveshaft sections, and install the new bearing and collar. To install the driveshaft, clean the transmission or transfer case area, slide the front of the driveshaft in and connect the companion flange. Raise the rear of the driveshaft, align the marks, and install the straps and bolts. For the front driveshaft on 4WD models, raise the vehicle and remove the skid plate. Mark the relationship of the driveshaft to the front differential flange and, on 1994 models, the transfer case flange. Remove the bolts and straps from the differential flange and, on 1994 models, the transfer case flange. On 1994 models, separate the driveshaft at the transfer case flange and lower it. In 1995 and later models, drop down the front end of the driveshaft first and slide it off the transfer case splined output shaft. To install, attach the front end to the front differential flange and install the straps and bolts. Extend or compress the driveshaft as necessary and attach the rear end to the transfer case flange, tightening all bolts to the proper torque specifications.

Disconnect the negative cable from the battery.