Universal joints allow drive shafts to move along with the suspension as the shaft is moving so power could be transmitted when the drive shaft isn’t in a right line between the transmission and drive wheels.
Rear-wheel-drive vehicles own universal joints (or U-joints) at both ends of the drive shaft. U-joints hook up to yokes that likewise allow travel shafts to move fore and aft as automobiles go over bumps or dips in the road, which efficiently shortens or lengthens the shaft.
Front-drive vehicles also use two joints, called frequent velocity (or CV) joints, however they are a several kind that also compensate for steering adjustments.
On rear-drive vehicles, one signal of a worn U-join is a “clank” sound whenever a drive gear is involved. On front-drive vehicles, CV joints typically make a clicking noise when they’re worn. CV joints are covered by protective rubber boots, and if the shoes or boots crack or are usually harmed, the CV joints will eventually lose their lubrication 
and become broken by dirt and dampness.
A U-joint is situated in both front wheel drive and rear wheel travel cars. Although they are different in design, they possess the same reason for giving the drive coach some flexibility. That is needed as all vehicles flex while in movement.
U-joints are located on each of the ends of the rear drive shaft, whereas CV-joints are found on front wheel travel cars. Each allows the travel shaft to rotate as the U Joint china differential techniques in relation to the rest of drive train mounted on the chassis.
The U-joint functions to save lots of wear and tear on your own vehicle’s transmission. Failure to possess a universal joint alternative done when needed can cause substantial destruction to your car in the future.
There are many indicators that U-joint or CV-joint is failing. They include: