1997 GP GT Trailing arms

[olopezm]

Hello people, the nightmare (that's me) is back! LOL.

The driver's side trailing arm broke last monday and the car has been sitting in my garage since then, I expect to be replacing it next week or the week after and I would like to know if there are any special considerations to replace it.

Since the arm broke when I was doing 40 MPH, I braked immediately and drove very slow (only with the car in gear and without accelerating) for about 60 meters until I could finally park and called the tow truck, after that I had to drive a little bit more to get the car into my garage, do you think any other part could have been damaged?.

I have no idea if the arms are sold in pairs or individually, do I have to replace both or is it enough to replace only the damaged one?. I still have to inspect the other.
Will I have to get the car re-aligned after the change?.
I've read in my Haynes manual that it takes only two bolts to remove each arm, are these hard to take off from the car?.

[Airjer_]

It should be fine. The two bolts should come out fairly easily.

[tblake]

If you live in a salty state like MN, start soaking them now with panther piss. I just replaced mine not too long ago. They came out hard, especially the bottom bolts. An impact air wrench would make the job way easier.

And I would definatly replace both sides at the same time, then get an alignment and you should be fine.

[olopezm]

Thank you guys, I'll let you know when I replace both arms.

Best regards...

[olopezm]

Hello guys, sorry to bring this post back from the death.

I had some problems at home and the dealer took a LONG LONG time to have both trailing arms in stock, but finally I'm ready to replace both trailing arms.

I want to ask you about something I read in my Hayness manual for the replacement.

"Do not tighten the nuts and bolts to the torque listed until the vehicle weight has been lowered onto the suspension".

Why is this necessary?
What happens if this procedure is not followed?
Did you do it that way tblake?

Best regards,

Oscar.

[Airjer_]

Once you tighten the bolts the bushings in the arms will be locked in whatever position they happen to be in. If the car is off the ground when tightened than the bushings will always have that twist preloaded on them once you lower the vehicle. Tightening them with the wheel in the natural position will keep them from having the preloaded twist constantly on them allowing the bushings to be in there natural neutral state.

[olopezm]

Oh that makes sense!. Thanks airjer, hopefully I will replace both arms tomorrow.

Best regards,

Oscar.

[tblake]

mine were tightened up in the air. I have had no issues. What repair manual is this?

There is a sleeve that is inserted into the bushing that the bolt tightens down onto, not the bushing itself, so i see no point of lowering the vehicle for the final torque. BTW, good luck getting a torque wrench in there with the car on the ground.

[olopezm]

Originally Posted by tblake

mine were tightened up in the air. I have had no issues. What repair manual is this?

There is a sleeve that is inserted into the bushing that the bolt tightens down onto, not the bushing itself, so i see no point of lowering the vehicle for the final torque. BTW, good luck getting a torque wrench in there with the car on the ground.

The manual is:

Hayness Repair Manual - 38010
General Motors.- Buick Regal, Chevrolet Lumina.- Oldsmobile Cutlass Supreme and Pontiac Grand Prix (3100 and 3800 engines)

All these models are covered in the same manual which is why some things aren't perfectly clear. I checked on another manual (Mitchell on Demand) and doesn't mentions anything about lowering the car before the final torque.

Yeah I know what you mean about getting the wrench under the car it's going to be a PITA to do it that way. Thanks for your help.

Best regards,

Oscar.

[olopezm]

Hello again!

Today I replaced both arms, it wasn't that hard to take them out ( I used some WD-40 also) I tried to follow the procedure mentioned in the Hayness manual but it really is impossible to tighten them with the car lowered, there is no space for the torque wrench to tighten the bolt on the chassis and on the knuckle side it's very hard to use the two wrenches at the same time with the wheel in position. So... to hell with it! LOL, I tightened everything while the car was in the air. Now I must have the car re-aligned before hitting the road and I also need to take care of a nasty p0441 dtc that doesn't seems to go away but that's another story.

I would like to share a gift that the previous owner (cheap bastard ¬¬) of my GP left for me:



You can clearly see that the broken arm (driver side) was already broken from before and the cheap bastard had it soldered instead of replacing it!, the other side was a bit twisted on the right side of the picture but I think still in a good shape; just in case I don't want to take the risk, maybe next time I won't be so lucky since I drive on the highway very often.

Well... I guess this is the end of everything related to trailing arms, thanks to both of you guys for your great help and your advice!

Best regards,

Oscar.

[tblake]

Good job!

I bet your car will handle better now too.

Your old ones don't look in to bad of shape, mine were a lot rustier when I took them out. Oddly enough mine hadn't broke yet.