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 your transmission and drive 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 go fore and aft as vehicles review bumps or dips in the road, which properly shortens or lengthens the shaft.
Front-drive vehicles also make use of two joints, called continuous velocity (or CV) joints, however they are a diverse kind that also compensate for steering alterations.
On rear-drive vehicles, one indication of a put on U-join is a “clank” sound whenever a drive equipment is involved. On front-drive 
U Joint automobiles, CV joints often make a clicking noises when they’re worn. CV joints are included in protective rubber boot footwear, and if the boot styles crack or are otherwise harmed, the CV joints will eventually lose their lubrication and become damaged by dirt and wetness.
A U-joint is situated in both front wheel travel and rear wheel drive cars. Although they will vary in design, they have the same purpose of giving the drive coach some flexibility. This is necessary as all cars and trucks flex while in movement.
U-joints are found on each one of the ends of the trunk drive shaft, whereas CV-joints are located on front wheel drive 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 lots of wear and tear on your vehicle’s transmission. Inability to possess a universal joint alternative done when needed can bring about substantial destruction to your vehicle in the future.
There are a few indicators that U-joint or CV-joint is failing. They consist of: