Broken Trailing arm

[rtanner]

So, i replaced the trailing arm rubber bushings with poly one about 6 month ago. I replaced all 8 bushings. last night while driving down a dirt hill I had to brake sort of hard and both upper trailing arms broke at the welds at the front end of the arm. Has this happened to anyone else? Any suggestions as to why this might have happened? The car travels about 10 miles of dirt road daily

[adamzan]

Just to make sure I read this right, they broke off the crossmember? Pics would help a great deal!

[RedPath88]

I am reading this as the arms themselves broke at the front of the main section. So the tube (at the front) where the bushings fit in broke off?

 

I have never heard of this happening, especially both at the same time! Were you travelling at a decent rate of speed, did you hit "really" hard and do impacts like this happen a lot?

[mws]

Highly unusual - this is the first I've heard of it happening.

 

When you replace them, use factory rubber bushings. Polyurethane bushings have very little "give" to them so will dramatically increase the peak dynamic loads the suspension members see. Over millions of jarring impacts, the metal will fatigue. There is pretty considerable design safety factor in the stock arms, but it would appear to not be enough to let you use poly bushings AND drive on a lot of rough roads. Eliminate one of those stress factors and you should be back in durable/safe zone.

[kmgar99]

:worthless:

[keelhaul]

did you use a torch to remove rubber bushings? if so then that may have weakened the steel and or welds.