Rear End offset

[highboostgn]

Does anyone have the link on how to fix the offset in the rear end? Mine has shifted a decent amount to the passenger side.

thanks,

 

[theCATman]

The way I've understood, the rearend doesn't move, and it shouldn't. It's tied to the frame via the 4-link & shocks.

What's moved is the body. This pretty much means there are badly worn bodybushings, or even completely broken ones allowing the body to shift around.

 

[SPOOLFOOL2]

Mine was offset about 3/8" from the factory. From what I've seen, this is not uncommon. I'd suggest getting adjustible upper control arms. This will allow you to perfectly center the diff under the car. You can also adjust the pinion angle.

Happy spooling.

Mike Barnard

 

[theCATman]

Mine was offset about 3/8" from the factory. From what I've seen, this is not uncommon. I'd suggest getting adjustible upper control arms. This will allow you to perfectly center the diff under the car. You can also adjust the pinion angle.

Happy spooling.

Mike Barnard

I'm not arguing with you, but I'm gonna argue with you.

We are both assuming different problems. However, he needs to figure out if the axle isn't centered under the frame, or is the body not centered on the frame. I'm betting it's the body.

Like I stated before, the axle is tied to the frame with the 4-link & shocks. If the axle wasn't centered, it would be dog-tracking. Yes, adjustable upper arms would correct this by pushing the one side back or bringing the opposite side forward. But, to me it sounds as though he's saying one wheel is sticking out right or left in the fenderwell. This would mean the body isn't centered on the frame, which is wayyy more common on G-bodies than a rearend that's not centered. This isn't a Turbo Regal issue, this is a blanket '78-'88 G-body issue.

I think the OP needs to do some carefull measuring & figure out where the problem lies before dropping big bucks on adjustable arms that may or may not be the issue. If it's the body that's off, torqing the rearend "straight" with adjustable arms would be creating more problems. Visually things would appear square, but in reality the suspension would be messed up.

 

[TRYMYSIX]

The inside of the tire is rubbing on the frame. A little piece of info the OP left out. So it sounds to me, the rear end is not centered in the frame. Maybe the OP will post up EXACTLY what problem he has. for example, which side is rubbing? the side that is not rubbing, how much space is between the tire and the frame? Does it rub all the time or just under hard launches? C'mon Donnie, tell us exactly whats going on:biggrin:

 

[highboostgn]

Its the drivers side that rubs under launch or if i get on it at any less than 50mph. Its leaving a constant mark about 3-4inches above the tire on the body . I measured this morning and got the same measurement tire to frame. So Im assuming its the body and I should replace the bushings.

 

[m233roller]

Mike is on the right track as Iv'e seen MANY turbo Buick cars that came from the factory with the rear ends NOT centered in the car. My own car only had 3000 miles on it and the rear end was almost 1/4 inch off to the passenger side. I installed all the missing body bushings and was still the same. Another friend of mine here had a low mile GN that the rear end was 1/2 inch off. I fixed mine with adjustable upper control arms.

 

[highboostgn]

I ll post some pics this afternoon

 

[highboostgn]

I got a better measurement and the driverside is closer to the frame by .25-.50"

 

[highboostgn]

 

[highboostgn]

It didnt rub when i had the tires on a 10" wheel..It started when I put them on the 8" wheels...im assuming it made the tire talller

 

[Jay Wicks]

Put the car on jackstands, take the tires off. Measure the distance from the frame to the inside wheel well and see if the body has shifted on the frame. Some cars were not centered well from the factory. You need to determine if the body is offset on the frame or if the rearend is not straight under the car before you do anything...

 

[highboostgn]

Put the car on jackstands, take the tires off. Measure the distance from the frame to the inside wheel well and see if the body has shifted on the frame. Some cars were not centered well from the factory. You need to determine if the body is offset on the frame or if the rearend is not straight under the car before you do anything...

Ok driverside frame to wheelwell is 3" and passenger side frame to wheelwell is 4.75"

 

[toofastforyou]

I've never seen a car with the rear axle perfectly centered from the factory. Mine, like most GN's I've seen, is a little more towards the right side of the car, nothing to be worried about unless it's by a large amount. I have some 10" wide wheels with a 1/4" spacer on the driver's side just to make the spacing even, but I could easily run the car without the spacer. It's the rear axle in relation to the FRAME, which is important more than to the body.
Also "theCATman", not to argue, but that's not what causes "dog-tracking". What causes this is the rear axle being set crooked under the car (meaning front to back measurement wouldn't be the same on both sides...)

Claude. :wink:

 

[theCATman]

Also "theCATman", not to argue, but that's not what causes "dog-tracking". What causes this is the rear axle being set crooked under the car (meaning front to back measurement wouldn't be the same on both sides...)

Claude. :wink:

I know, that's what I said. That's why I said adjustable upper arms would fix that by pulling one side forward, or pushing the other side back.

Maybe I'm missing something here, but I just don't see how a lateral difference can be from the rearend not being centered , unless the bushings in the control arms are that worn. How can the rearend not be centered, unless the control arm mounts aren't precisely welded in the same place, varying from frame to frame.

Him saying 1 3/4" difference from frame to wheelwell, that's a body issue. The frame isn't going to move. That will be a constant. Now the body could very easily be off that much & if the body bushings are worn it could be floating around or have shifted over time.

Now if it were 1 3/4" difference from frame to backside of the tire, that would be a non-centered rearend.

I think the tire rub is just what he said it's from, switching to a taller tire.

IDK.... I've given my thoughts & reasons. "highboostgn" keep us up to date on what you find out.

 

[SPOOLFOOL2]

Ok driverside frame to wheelwell is 3" and passenger side frame to wheelwell is 4.75"

Wow, Has this thing been hit? Your telling me that the body needs to shift almost an inch, to get it back inline with the frame rails. You may have issues, other than body bushings or control arms. Side note for you and others: Adjustible upper control arms help two fold with rubbing problems. They allow you to center the rear end for best frame and fender lip clearance. They also reduce side to side flex.

I would definitely try and figure out why your wheel well is 1 3/4" bigger on one side (recheck the number). I know that these things weren't put together with a micrometer, but Dang!

Let us know what you find.

Mike Barnard

 

[QUIP'6']

It didnt rub when i had the tires on a 10" wheel..It started when I put them on the 8" wheels...im assuming it made the tire talller

not taller it made it have more sidewall bulge.on the 8 inch rim thats why you can go with a wider rim and deeper backspacing because it straighten out the sidwall. i would put a 1/4 in spacer on that side

 

[highboostgn]

not taller it made it have more sidewall bulge.on the 8 inch rim thats why you can go with a wider rim and deeper backspacing because it straighten out the sidwall. i would put a 1/4 in spacer on that side

thanks man ill probably do that til I can get the bushings put on