Is my trailing arm bent??

[turner.e30]

In the process of doing a rear subframe refresh. I’m putting everything back together and my right rear trailing arm is not fitting back into the subframe. Everything came apart fine and I did not modify it - only sent it off to be blasted and coated. I’m running Garagistic poly bushings. What’s going on here? Is something bent or twisted?

[rturbo 930]

You sure you have the bushings in the right way around?

[turner.e30]

You sure you have the bushings in the right way around?

Pretty sure. Fat part on the outside, right? Other side fit fine.

[rturbo 930]

Looks like you have it right.


Looking at it more closely, it doesn't look like that difference would fix your problem anyway. Maybe measure it against the other one? That's really strange, and I can't imagine how it could bend that much just from blasting it.

[ForcedFirebird]

They may have sent you a bent arm. Not sure they refurb your particular parts? More than likely they get cores in, and have a sort of assembly line process. They sent a customer a bent arm, we couldn't get the camber right on one side, so stuck a digi protractor on it and the bearing- hub-to-spring-perch angle was off like 3°. Just sucked that the car was already together and on the alignment rack when it was discovered - but in the end Garagistic honored the return, but the customer had to pay our labor (and the alignment shop) a second time. :/

[turner.e30]

They may have sent you a bent arm. Not sure they refurb your particular parts? More than likely they get cores in, and have a sort of assembly line process. They sent a customer a bent arm, we couldn't get the camber right on one side, so stuck a digi protractor on it and the bearing- hub-to-spring-perch angle was off like 3°. Just sucked that the car was already together and on the alignment rack when it was discovered - but in the end Garagistic honored the return, but the customer had to pay our labor (and the alignment shop) a second time. :/

It's definitely the arm that I sent in. I sent it to a local place to have it blasted and powdercoated - not to Garagistic. I'm just scratching my head on how it came off the subframe so easily if it was bent so much. I did use the threaded rod method to get the old bushings out. Would that be enough force to bend the arm? I wouldn't have thought so, but who knows...

[turner.e30]

I took the arm to a pretty reputable frame shop in town this morning and they wouldn’t even attempt to straighten it. Has anyone had luck fixing a bent T arm?

[E30andy]

If it was bent you would think you would see some damage or a crimp somewhere on the TA where the bend occurred. This is very odd. I am in the process of refurbing my rear suspension and subframe and used the same method to remove the TA bushings and no way could you bend the TA using the threaded rod method. The rod would bend or break before the TA would bend.

Did you talk to the powder coater? They use alot of heat to perform powder coating, maybe something happened to the TA when it was heated that bent it? Longshot but hard to come up with any other explanation.....

[turner.e30]

If it was bent you would think you would see some damage or a crimp somewhere on the TA where the bend occurred. This is very odd. I am in the process of refurbing my rear suspension and subframe and used the same method to remove the TA bushings and no way could you bend the TA using the threaded rod method. The rod would bend or break before the TA would bend.

Did you talk to the powder coater? They use alot of heat to perform powder coating, maybe something happened to the TA when it was heated that bent it? Longshot but hard to come up with any other explanation.....

Agreed. I looked it over pretty carefully and couldn't find anything obvious. I did ask the powdercoater and they didn't seem to think the process could have caused any damage, and I agree with them. It's baked at 400 degrees which I wouldn't think would affect anything.

I'm going to take it around to a couple other shops to see if anyone would make an attempt at straightening it out. The first shop I took it to wouldn't touch it because they were worried about it collapsing under pressure.

[Vincenze]

You can use the threaded rod tool to expand it.
Or is it too wide? Then the threaded rod tool should be able to compress it too.

You may try regular rubber bushings as they are more forgiving.

[tomstin]

Looking at that picture, have you tried dropping the arm in from the top versus in from the rear? Those tabs appear to be on a bit of an angle (pictures are tough to judge) and coming in from the top MAY make a difference.

I doubt if the powder coat heat had an effect. It may however added a mil or two to the thickness of those tabs???

[turner.e30]

Looking at that picture, have you tried dropping the arm in from the top versus in from the rear? Those tabs appear to be on a bit of an angle (pictures are tough to judge) and coming in from the top MAY make a difference.

I doubt if the powder coat heat had an effect. It may however added a mil or two to the thickness of those tabs???

I did try that, yes. No luck.

Looking at it, it seems that if I reversed the bushings it may fit. Anyone know if this would have any major consequences as far as alignment is concerned?

[Shifty_K]

What ended up being the cause? I am having the exact problem.

[moatilliatta]

You can take your subframe out and set it on a level table. Bridge the right side mountings point with a m12 rod, repeat on the left. You can now measure the subframe mounting points angles.

A lot of work. but you can rule it out..

[Shifty_K]

Thanks for replying.

I get what you're saying but both arms appear to be out the same amount and with the gusseting on the mould of the arm it seems unlikely they'd warp from a powder coat oven, I'll take some measurements tomorrow and see if I can figure it out.

I reinstalled both bushings with the thick collar on the inside and can get it installed but the last bolt holes are still off about 1/8th of inch, seems like it might go if I reposition the subframe and arm so I can maneuver better.