Originally Posted By: A_Harman
Originally Posted By: Shannow
Originally Posted By: LubeLuke
I have had many standard Subaru and Mitsubishi studs fail. To determine the exact cause you would need to send them in for specialised testing, as it is impossible to tell by looking if they were damaged during installatio or removal.
You can tell a LOT from the fracture face.
Beach marks. Cup and cone surfaces at point of final fracture.
What happens when the studs threads are stripped by the nut, but the stud is not broken? This is the most common problem I have personally seen. Although often after the studs threads are ruined, the nut will become stuck. The easiest way for removal then is repeated on/off with an impact wrench until the stud fails.
How can you determine if the failure was from over torqueing the nut, or from excessive load caused by the wheel and tire? It seems as though both would cause the same stretching of the threads.