Upper Control Arm Interference

[Patrick]

My passenger side GW UCA is hitting the Upper Control Arm Mount. It appears that this mount is about 3/16" back on the subframe. The bolt holes are positioned correctly for alignment purposes but are offset in the mount..causing the rear of the control arm to hit.

Any suggestions on a fix?

[chicane67]

Is this at full droop ?? Do your droop stops contact the frame in the correct location ??

[Patrick]

The interference is so bad that it doesn't matter if is at full droop or not. And by 'droop stands' are you refering to the mount itself? The mount on the passenger side is set back about 3/16" when compared to the driver's side. The holes are drilled in the correct position..but since the mount is set back.. this causes the control arm to hit.

[chicane67]

Droop stops.... the rubber bumpers on the (underside of) control arm itself which limits downward travel.

I myself havent worked on a chassis that was as bad as you have described..... but I have had a few that I had to rework to get a little more clearence when modifing the geometry. This sounds like the mount was welded to the frame in an incorrect location from the factory and the holes were drilled into an offset bracket...... which I am sure isnt impossible. Its either that or when the bracket was bent before welding, it was not bent to spec....

[Patrick]

Should I cut off the mount and re-weld it in the proper position-- I would also have to drill holes in the proper position.

I was considering the G-Mod- by moving the holes down and back, do you think I can get the clearance needed?

[David Pozzi]

I'd do the Guldstrand mod, it will move the arm to the rear a little, maybe 1/4"? I'd have to check the template.
since you have tubular arms, the tops of the mounts won't need trimming, check arm clearance to the braces to the mounts.
David

[baz67]

I second David. You will get better front geometry too boot.

[TUBED]

What's the chance the cross shaft needs to be pressed out of the control arm and be flipped end to end or turned around. Is there any offset difference there or maybe it was assembled incorrectly?

[69protour]

Hey Patrick, I had the same problem with mine also. I called GW and they said they would doubt their arms were wrong, being built in a jig. They did say, and I've talked with other people that when GM built the subframes, all were not very exact. So with my subframe already powdercoated I was thinking what in the hell am I going to do. So I carefully ground off material on the top mount where the a-arm was rubbing, then took some POR-15 and covered the bare metal. You can't even tell where I did it. Your not going to be taking enough material off to weaken the top mount either. It was kind of a pain in the ass to do but with aftermarket pieces your bound to have to do that once in a while. Hope this helps. Trond