A driveshaft is a hollow tube that transfers power from the transmission to the differential. It has moving joints between the two ends and the middle of twin-shaft systems. In a single-piece rear driveshaft system, one end goes straight into the transfer case or transmission, and the other has a special connection to the middle part of a two-piece driveshaft, making it move when you drive. Two-piece rear driveshafts have a central support bearing attached directly to the frame crossmember underneath the vehicle, and 4WD models have a joint on the front driveshaft that can move to keep up with length changes. You only need basic maintenance for your driveshaft setup. Universal joints automatically get lubricated when they are needed, while any repair jobs mean taking the driveshaft out of the car. Checking the driveshaft for damage, keeping it clean, making sure balancing weights stay in place, and re-installing it in the same spot is what we need to do to keep things running right. When you hear noise or feel vibration while driving, a road test helps us find what's wrong with the driveshaft. To inspect the driveshaft properly, the car has to be lifted stable while blocking the wheels to stop it rolling. Looking at your driveshaft and spotting dents or cracks matters. Oil escaping from the front or back shows a broken seal. When you look under the car, you can check the universal joints by turning the wheel, and unusual sounds from the center bearing tell you the bearings might be worn out. You can tell if the universal joint needs replacement by twisting it and making sure the mounting bolts are tightened. To check the front driveshaft on 4WDs, look for oil leakage coming from the slip yoke and from the areas where the driveshafts meet the transfer case and front differential. Seals worn out by oil leakage need to be replaced. When examining the front driveaxles, watch for loose components. Also look for rubber boot repairs between the joint and axle ends, as oil leakage near axle connections means the oil seal is damaged, while grease leaks from the boots shows a torn gasket.