rear ends not centered?

[topfuel]

I know this has been brought up before but I couldn't find any threads.

Where do I need to look to fix this problem?
I didn't measure but it looks like my rear end is about an inch off center to the body, one wheel sticks out of the well and the other one doesn't.

Is this body misalignment or a rear end alignment problem?

 

[QUIP'6']

i would look at the back of the wheel well and see if both sides are the same. if not then there is your problem. if not maybe the rear wheel was hit or slid into a curb hard or something else. check the trailing arms for damage

 

[topfuel]

Okay I just did a quick measurement of clearance between inside of rear tire and frame on both sides and come up with about a quarter inch difference.

The other 3/4 to 1 inch must be the body not centered on the chassis?

 

[Boost231]

mine is the same way. Body is not perfectly straight on the chassis which is common with these cars. Once you start getting big tires under the car is when you notice. I never noticed till i was putting on different wheels and tires

 

[QUIP'6']

the back wall of the wheelwell should be even with the frame check that

 

[Alky V6]

Mine was offset. I used offset spacers on the control arms to fix it.

 

[topfuel]

It is the body, I just checked body to frame and it's off pretty far.

I just found a body bushing thread that explained the situation.
Going to replace the body bushings and try to square up the body.
ughh it's a midwestern car so I'm sure things are rusty under there

 

[charlief1]

Mr. Kirban has stated before that without the "GNX" bushings the chasis will be off center. The bushings that are missing will not align the chasis on the frame.

 

[topfuel]

Yes this was the thread I found, Kirban chimed in a few times.

http://www.turbobuick.com/forums/general-turbo-buick-tech/335025-body-bushing-suggestions.html

I went to Kirbans site to see what he has for bushings but couldn't find any

 

[Dennis Kirban]

Yes this was the thread I found, Kirban chimed in a few times.

http://www.turbobuick.com/forums/general-turbo-buick-tech/335025-body-bushing-suggestions.html

I went to Kirbans site to see what he has for bushings but couldn't find any

They are not yet on ourwebsite but we have the complete 22 bushing kit includes gnx ones and on sale til April 16th...$249.95 and you get all the correct grade 8 bolts as a bonus a $27.95 value...these are the OEM style bushings....

postions 2 thru 7 uppers & lowers position one is a core support bushing which we also sell by itself...

need to call my office to get the deal...

should be in stock.

denniskirban@yahoo.com

 

[Dennis Kirban]

As for body to frames...

I have met at several GS NATs a Buick employee engineer type guy....

Every car when it was built meaning the Regals was slightly off center....it was not corrected because it wasn't off enough to justify fixing it.

So, now add 20 plus years to the mix and having 4 or 6 missing or left out bottom body bushings, and maybe rust issues and that slightly off center now is maybe one inch or more out of wack.

This becomes very evident even to non tech people like myself when you go and put larger tires and rims on the back and you notice one side almost rubs the outer frame rail and the other side has a wider gap.

Most of us only see the various gaps to the trunk lid and rear quarters and hood to fenders or doors to fenders.....quality control has come a looong way since our cars were built.

denniskirban@yahoo.com

 

[SPOOLFOOL2]

It may just be the rear end.

My rear end (on my car) was about 3/8" off centered when I got it. This, I found out when I tryed to fit a 275/60/15 tire under the back. The fix was to get adjustable upper control arms, to be able to move the dif from left to right. Also, adjust pinion angle. Measure from inside the rim beads to the frame rails. If this gap is the same, then I'd work on getting the body centered on the frame. Good upper and lower control arms will also help stiffen things up and keep things from rubbing with wider tires.

Good luck.

Mike Barnard

 

[Alky V6]

My rear end (on my car) was about 3/8" off centered when I got it. This, I found out when I tryed to fit a 275/60/15 tire under the back. The fix was to get adjustable upper control arms, to be able to move the dif from left to right. Also, adjust pinion angle. Measure from inside the rim beads to the frame rails. If this gap is the same, then I'd work on getting the body centered on the frame. Good upper and lower control arms will also help stiffen things up and keep things from rubbing with wider tires.

Good luck.

Mike Barnard

I thought of using my adjustable control arms to pull the rearend to center, but then realized the control arms would not be at symmetrical angles in relation to the car centerline. That's why I decided on spacing the control arms over.

 

[SPOOLFOOL2]

I thought of using my adjustable control arms to pull the rearend to center, but then realized the control arms would not be at symmetrical angles in relation to the car centerline. That's why I decided on spacing the control arms over.

I see your point, and the centerline on these car's may not be centered on the UCA mounts in the first place. When I centered the dif under my car, everything just fell into place. The tire gaps between frame rails and fender lips were now the same. If doing this threw the UCA geometry off a bit, I don't think It's hurt my performance any on my ten second car. On your eight second car, having the UCA's different lengths "may" drive the car to the left, to the right, or bind up. My car launches straight as an arrow, and has done 1.39 short times. The back end does always seem to go to the left a bit, comeing out of the burnout box. I just figured that the ground was sloped, or one front brake grabed a bit better than the other. Also, if my rear right tire was forward of my rear left tire, this would cause the back end to go to the left, or drive the car to the right. UCA would not adjust this. It would need to be fixed with the LCA's.

Good discussion.

Mike Barnard

 

[topfuel]

Mine was offset. I used offset spacers on the control arms to fix it.

Not sure what you mean here by offset spacers?
The sleeves inside the bushings?

 

[Alky V6]

Not sure what you mean here by offset spacers?
The sleeves inside the bushings?

I'll post some pics. It will be easier to explain with the pics.
It wouldn't work with stock control arms. You need some room to space the control arm ends over to one side of the bracket. It's not a perfect solution. You still end up with some geometry compromises.

 

[Alky V6]

Here are some pics.
You'll notice that I split the amount of offset between the front and rear mountings in the lower control arms.
All of the offset was done on one end of the upper control arms. The design of the UCAs didn't allow any offsetting of the chassis end mountings.