A universal joint is a linkage of sorts that transmits the rotation of a shaft that goes from the engine to the transmission in a vehicle of a rear wheel drive car. Or, longitudinal in design.. From the rear of the transmission to the differential assembly. The universal joint is used in almost every class of machinery from cars, trucks, machine tools, instruments and control devices.
To get a better idea of the need for a flexible joint on the ends of a drive-shaft, you have to understand that the rear of the transmission and the front of the differential, which is where the two joints attach to are on two different axis’s. Thus the need.
The variations in angular displacement and angular velocity between the two drive line components is a big issue in many automotive setups, and can be eliminated by using two Hooke’s joints, with an intermediate shaft in some cases. This arrangement is very conventional for an automobile drive shaft.
Cardan Joint: Also known as a Hooke Joint, Universal Joint or U-Joint, it is a simple flexible coupling using a double yoke and four-point center cross. Cardan joints are used as couplings in the drive-shafts of rear-wheel drive cars.
The technical data is really not really what is important. What is important is making sure your U-joints are examined periodically and if they need replacing, buy an American made product. The cheap ones are just that, cheap and not very safe. If a front universal joint breaks at speed, a very dangerous situation can occur as the drive-shaft digs into the pavement.
Don’t forget to check the lubricant in the transmission and rear differential if you don’t want trouble with them. Call GotTransmissions.com for more information, or use our blog as a free source of information. Got an automotive question, feel free to ask it? 866-320-1182.