* Belt slippage or breakage: This could cause the engine to overheat or other serious damage.
* Tensioner failure: The tensioner could seize or malfunction, again leading to belt problems.
* Damage to surrounding components: A failed JB Weld repair could damage adjacent parts.
Instead of using JB Weld, you should:
* Use a bolt extractor: This specialized tool is designed to remove broken or stripped bolts.
* Replace the bolt with a new one of the correct size and thread pitch: This is the best solution.
* Replace the entire tensioner: If the threads are severely damaged, it's safer and more reliable to replace the entire belt tensioner assembly.
Attempting a JB Weld repair is a risky shortcut that could cost you far more in the long run. It's far better to invest a little time and effort in a proper repair.