A driveshaft is a tube on one or two of them transmitting power from the transmission or the transfer case in 4 wheel drive models to the differential with universal joints at the two ends and in the center for two part driveshafts. Single piece driveshafts have splined yoke at front to slide in the transmission housing for accommodating suspension movements; there is an oil seal to avoid leakage of fluids and dust; if leakage is observed the seal must be replaced. Two-piece driveshafts employ a slip joint at the forward end of the rear extension and comes with a support bearing that is a pre-lubricated ball type bearing provided in a rubber cradle. In general, driveshaft assemblies need little service, and universal joints are permanently lubricated and must be changed if there is a problem Removal is usually from the car. It is important that the driveshaft should not be covered with fats and dust to make it balanced so whenever disassembled, it must be placed again to the right side. Malfunctions in the driveshaft are characterised by noises or vibrations that occur when driving, therefore necessitating a road test. For inspection the rear of the vehicle should be raised and supported safely and then inspected for any dents or cracks in the driveshaft tubing in which case the driveshaft tubing will have to be replaced. Front or rear leakage means seal defects possible, and rotating rear wheel reveals proper functioning of universal joints, noises from centre bearing. One can also check the universal joint while the car is not in motion by trying to twist it; in case it is possible to twist it, then this is a sign of wear. Also the mounting bolts for the driveshaft should be checked to see that they are still tight. On the 4WD models, similar examinations should be done on the front driveshaft and in particular, examine the grease leakage around the sleeve yoke and where the driveshafts connected to the transfer case and front differential; also check the front driveaxles for looseness and front rubber boot s and the axle ends for any grease/oil leakage.
