Universal joints allow travel shafts to move up and down with the suspension as the shaft is usually moving so power can be transmitted when the drive shaft isn’t in a directly line between the U Joint china transmission and travel wheels.
Rear-wheel-drive vehicles include universal joints (or U-joints) at both ends of the drive shaft. U-joints hook up to yokes that as well allow 
travel shafts to move fore and aft as cars go over bumps or dips in the street, which effectively shortens or lengthens the shaft.
Front-drive vehicles also make use of two joints, called continuous velocity (or CV) joints, but they are a distinct kind that also compensate for steering adjustments.
On rear-drive vehicles, one indication of a worn U-join is a “clank” sound whenever a drive equipment is involved. On front-drive vehicles, CV joints quite often make a clicking noise when they’re donned. CV joints are covered by protective rubber shoes, and if the shoes crack or are or else destroyed, the CV joints will lose their lubrication and be damaged by dirt and dampness.
A U-joint is situated in both front wheel travel and rear wheel drive cars. Although they are different in design, they possess the same purpose of giving the drive teach some flexibility. That is required as all vehicles flex while in action.
U-joints are located on each of the ends of the trunk drive shaft, whereas CV-joints are located on front wheel travel vehicles. Each allows the travel shaft to rotate as the differential techniques in relation to the others of drive train installed on the chassis.
The U-joint functions to save wear and tear on your own vehicle’s transmission. Failing to get a universal joint substitute done when necessary can bring about substantial destruction to your vehicle in the future.
Here are a few indicators that U-joint or CV-joint is failing. They consist of: