I Want To Know Why My Rear Right Wheel Studs Have Broken Twice?what May Cause A Wheel Stud To Brake??thanks For Your Feedback..

 

One cause would be over-torquing the lug nuts.

 

breaking, and +1 on the overtightening. Do you have spacers by chance?

 

no spacers..but i dont think i over tight them..when i tight them it will be by hand..how much should be the torque??

 

80-85 ft-lbs

 

I broke 2 studs just taking them off now I freaking stock them cause you never know

 

What kind of car is it on and does it have an lsd? One thing you have to realize about a non-lsd drivetrain is that the right rear wheel receives torque first under normal conditions, so hard launches in the car would be harder on your right rear wheel than your left rear. That coupled with over tightened lugs could be enough to only shear them on that one side.

Post some pics of the broken ones, failure from overtightening should appear different than shear failure. If the studs narrow or neck up near the failure point, then it's definitely overtightening. If they shear at an angle, somewhere near 45 degrees usually, then it's probably a shear issue. They shouldn't shear on their own though unless you're putting down a lot of power to a non-lsd rear end with some really sticky tires, like Mickey Thompson slicks sticky. That being highly unlikely, though not impossible, my guess is overtightening. 90 lbs should be good, especially on aluminum wheels.