broken motor mount wtf

[eksplosivejoe13]

I was installing a k-member on my mustang today, and i got it all aligned everything, when i was tightening up the motor mount nut that goes through the k-member, the stud on the motor mount broke. the motor mounts are from prothane and i contacted them, hopefully they'll sent me a new one. has anything like this happened to anyone else? whats the likely hood of prothane giving me a new set?

 

[duff daddy]

How old are the mounts? miles? Depending on that info will then give you the answer you want. If you go in there demanding a new set, that wont get you very far. But if your being real with the guy and being legit and not dink, they will probably help you out.

 

[eksplosivejoe13]

the mounts are like 15 months old. maybe like 3000 miles on them. i'd be happy if the replaced the broken mount, but i'm worried that the other one might break also. is it possible for the mounting studs to fatigue from heat from the headers or something?

 

[duff daddy]

Well you have a valid point, however with most aftermarket parts there isn't much of a guarantee due to the nature these cars are intended, straight line or roundy round. Personally I would call them, let them know who you got them from, let them know a date and how much, and say your interested the failed parts replacement. If you have to pay shipping on the old/new part, do it. Just work with them. As far as the actual failure, could be the stud was made of poor quality alloys, too many impurity's, or could have been damaged later on. If your thinking your car go that hot that it could be excessive heat from the headers, your car is way to lean! I doubt it was exhaust gas temps which caused the failure unless you let it run at 5k in 130deg heat for the past 14 months.

 

[bjorkmae]

If the headers got the mounts hot enough to actually change the physical properties of the metal then any wiring nearby would be melted though. Also if it was to heat the metal up enough to change anything then it would have softened the metal and that would have resulted in either stretching on easily stripped threads. But from the description it sounds like it snapped off and if that is the case that would mean it would have been hardened. To harden metal you have to get it hot and then quickly cool it down with water. The temps that occur under the head aren't capable of doing this. Probably just a bad part.

 

[mike97gt]

is there any rust on the broken part of the stud? that will tell if there was a crack beforehand or not.
also does it look like it stretched and broke or just snapped?

they will probably ask what you were torquing it to as well.