Steering U joints

Universal Joints

Universal joint, U joint, Cardan joint, Hardy-Spicer joint or Hooke's joint - call it what you like, it's used universally (pardon the pun) in all kinds of transmission shafts. The first cars had them (it was Henry Ford who named it the "universal joint"), and now you have come here looking for universal joints.

Browse the products on these pages for deals on universal joints, steering U joints, CV joints, and other auto parts.

Universal joints

What is a Universal Joint?

A universal joint is a joint or coupling that allows two rotating parts of a machine (most commonly two shafts), that are not in line with each other, limited freedom of movement in any direction while transmitting rotary motion from one part to the other. Universal joints allow a driveshaft to bend or flex around the joint without breaking or losing rotation.

A simple universal joint, known in English-speaking countries as Hooke's joint and in continental Europe as a Cardan joint, is shown in the animation at the top of this page. Simple u-joints suffer from uneven transmission of angular velocity or rotation speed, with the rotation of the driven shaft becoming more irregular the greater the angle with the driving shaft. The variation in angular velocity between driving and driven shafts can be eliminated by using two Hooke's joints, with an intermediate shaft. This arrangement is used for an automobile driveshaft.

More sophisticated universal joints which are designed to overcome the problem of irregular rotational velocity are known as constant velocity joints or CV joints for short.

U joints