Universal joints allow drive shafts to move along with the suspension while the shaft is certainly moving so power could be transmitted when the travel shaft isn’t in a direct line between the transmission and travel wheels.
Rear-wheel-drive vehicles have got universal joints (or U-joints) at both ends of the drive shaft. U-joints connect to yokes that as well allow drive shafts to move fore and aft as cars go over bumps or dips in the street, which successfully shortens or lengthens the shaft.
Front-drive vehicles also work with two joints, called regular velocity (or CV) joints, nonetheless they are a numerous kind that also compensate for steering adjustments.
On rear-drive vehicles, one indication of a worn U-join is a “clank” sound when a drive equipment is engaged. On front-drive vehicles, CV joints quite often make a clicking sound when they’re put on. CV joints are included in protective rubber boot styles, and if the boot footwear crack or are otherwise damaged, the CV joints will eventually lose their lubrication and become harmed by dirt and moisture.
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 U Joint giving the drive train some flexibility. That is required as all cars and trucks 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 autos. Each allows the drive shaft to rotate as the differential movements in relation to the rest of drive train installed on the chassis.
The U-joint functions to save wear and tear on your own vehicle’s transmission. Failing to possess a universal joint alternative done when required can result in substantial damage to your car in the future.
There are 
a few indicators that U-joint or CV-joint is failing. They consist of: