The drive shaft is the axle that connects the two parts of the drive train (front and rear). The drive shaft transfers torque--the force used to rotate an object--between the two components. The torque subjects the shaft to intense pressure and wear. It is not unusual for a drive shaft to need to be replaced during the lifetime of your vehicle. In addition, some people may want to upgrade their drive shafts to handle the increased torque needed by high-performance cars. You will need to measure the drive shaft length to find an appropriate replacement. The process is easy and takes only a few minutes.
Park your vehicle on a level surface and engage the parking brake.
Identify the type of drive shaft connection that you have. While there are many very specific types of drive shaft, there are three common types of connections. Either your drive shaft is mounted to your vehicle using a "U" joint and yoke at each end, or it is connected by being bolted to a flange at each end, or it is a one-piece drive shaft that comes off your transmission and connects into a cap mount on the rear differential.
Measure a double "U" joint drive shaft by holding your tape at the center of the joint and measuring to the center of the opposite one. The center of the "U" joint is found by measuring the width of the joint and then the thickness. Where these two measurements cross is the center of the joint.
Measure a drive shaft connected by flanges by holding your tape to the inside face of the flange and measuring to the inside face of the opposite one. If your drive shaft is one of the rare ones that uses one flange mount and one "U" joint, measure from the inside face of the flange to the center of the "U" joint.
Measure a one-piece drive shaft by holding your tape at the very end of the transmission shaft and measuring to the very beginning of the cap of the opposite joint end. The cap is the cover that the drive shaft is inserted in to provide torque to the rear differential.
Look at the drive shaft and copy down any information labeled or stamped on it such as the manufacturer and model number. This will help you to match a replacement.
