my rear ujoint wore out after 3 months

my rear ujoint wore out after 3 months, what could be the cause of that?

Could be... crappy brand, excessive operating angle, not enough grease, install failure (caps binding), etc. What brand and how did they fail?

Because you told us no information on your set up is why.


Lift? Rear axle? SYE? What type of u-joint? What kind of driveshaft? Angles?

Setup, age of rig, model, which end of the shaft, all would help. But for starters, I'll mention that I've had trouble with high mileage Chrysler 8 1/4 rear ends when the pinion yoke wears out. There are little ears that hold the caps tightly at the end, and they can wear out. When that happens, even a little, no matter hot tightly you sock down the straps, the caps will push out a little, and then the joint will hammer itself to death. Don't pinch pennies and recycle the straps. New ones are designed to stretch a little when you tighten them.