Question about rear trailing arm bolt...

[littlehoov]

Hey folks, Ill save you all the long stories and simply say that I had to replace one of my rear trailing arms.


My question is this, is the lower bolt that goes through the knuckle supposed to have a large washer on its head? I I had to get all new hardware back there, bolts included, and in the diagrams I pull up I dont see a washer.

It sort of looks like my other side (still factory hardware) has a washer, but I havent looked closely enough and I thought they might have slightly changed the bolt used or something.

Long story short, my new repair just effed up and pulled the bushing completely out of the trailing arm after a day or two of driving, but I had simply put just the bolt in.

I need to know if it has a washer, where might be the best place to the appropriate one (since GM doesnt list one) or if this is just some sort of freak accident. The other option is that my unibody is somehow twisted, this car has some pretty severe rust issues, and the old trailing arm was twisted for quite a while before it finally broke...and I dont know the history as to why.

Trying to shed some light on this and get it fixed....again....HELP!

 

[Sven the Sexman]

My guess is you tightened the bolt with the suspension at max extension...aka wheels off the ground. The bolt needs to be torqued at ride height. It shouldn't have hurt anything but unfortunately yours did.

 

[littlehoov]

That is true, I did torque it down with the wheel in the air, or wheel off actually.

 

[Sven the Sexman]

Most people do...don't feel bad. LOL

 

[littlehoov]

I'm still curious about this washer business, seems like a washer wouldnt make much difference to me, yet there is one on the other side, either that or that bolt has a huge flange on it...yet no diagrams show one....Thanks GM!

 

[Alix0r]

The washer helps let the arm move up and down... so if you just tighten down the bolt you will pinch the bushings so they cant move

 

[littlehoov]

Well theres yer' problem right there...

It just straight up popped the bushing out of the arm, crazy stuff I tell ya...

I do feel like I need to get a washer now after examining the other side, it seems as though the washer prevents the arm itself from separating from the bushing if there is side to side movement like from cornering, etc...it makes sense to me because on the other side, the washer is the same diameter as the metal portion of the arm....

Anyone have a parts car? haha

 

[littlehoov]

Just updating this for future reference, I was able to find a new washer, I had to go to the dealer because none of the online diagrams were detailed enough to show it.

It is GM part # 10268814.