A driveshaft is a tube, or a pair of tubes, that transmits power between the transmission (or transfer case on 4WD models) and the differential. Universal joints are located at either end of the drive shaft and in the center on two-piece driveshafts. Single-piece rear driveshafts employ a splined yoke at the front, which slips into the extension housing of the transmission. Two-piece driveshafts have a center support bearing. The universal joints are lubricated for life and must be replaced if problems develop. Problems with the driveshaft are usually indicated by a noise or vibration while driving the vehicle. To inspect the driveshaft, raise the rear of the vehicle and support it securely on jack stands. Block the front wheels to keep the vehicle from rolling off the stands. Release the parking brake and place the transmission in Neutral. Crawl under the vehicle and visually inspect the driveshaft for any dents or cracks in the tubing. Check for oil leakage at the front and rear of the driveshaft. Have an assistant rotate a rear wheel so the driveshaft will rotate and make sure the universal joints are operating properly without binding, noise or looseness. Listen for any noise from the center bearing (if equipped). Check the rubber portion of the center bearing for cracking or separation. Check the driveshaft mounting bolts at the ends to make sure they're tight. On 4WD models, the above driveshaft checks should be repeated on the front driveshaft, as well. Check for leakage where the driveshafts connect to the transfer case and front differential. Check for looseness in the joints of the front drive axles. Also check for grease or oil leakage from around the drive axles by inspecting the rubber boots and both ends of each axle.
