Offset rear end in GM vehicles

[ScottT]

I know the rear ends are offset to one side. Do people usually narrow the one side so that they can run the same bs on both wheels and have them tucked in the same amount? Maybe like 1/4 or 1/2 inch on one side? Maybe the difference is so small no one can notice, just been reading up on it and wasn't sure, had hear that ford makes one side shorter to make up for the difference but gm doesn't. Thanks guys!

[Roadbuster]

On my GTO the rear wheels are the same backspace and I run 18x11 rear wheels with very little clearance. Both sides are the same.

I have heard of many vehicles with a offset rear but that is not by design.

Jon

[ScottT]

I just thought thats the way it had to be, heard you can't have the rear end dead center for some reason. I remember reading about this long ago in popular hot rodding

[b-man]

Due to production tolerances the body of a full-framed car (A-body) may be sitting about 1/2" to one side in relation to the frame.

On a unibody car (F-body) the rear frame rails also may be off a bit to one side in relation to the body, again due to allowable production tolerances.

On the full-framed cars it's possible to move the body over on the frame to get things pretty even from side to side, I recently did this on my '64 Tempest while putting in a new set of body mounts.

On the unibody cars you'll just have to live with the slight difference in fender clearance from side to side. I've never heard of anyone putting different offset rear wheels on their GM car, the rear end is centered in the frame/framerails but not perfectly centered in relation to the body itself.

Using different offset rear wheels on each side would cause the car to track funny. Narrowing the rear end a different amount on each side would do the same thing.

[ProdigyCustoms]

You would narrow the sides equally, if you build a new rear you need to build 1/2" pinion offset into it.

[montessaj]

My Monte Carlo is 1/4" over on the driver side.

[DRJDVM's '69]

Wait...are you referring to where the pinion yoke is to the end of the axle flange?

Its not dead center in alot of cars..... in other words if you measure from the pinion to one flange and compare it to the other side, the measurment wont be equal.... the pinion is offset to one side to help vibration and get the u-joints bearings to rotate correctly

The entire rearend should not be offset to one side.....but with factory tolerances, some are and thats why the tire gap may not be equal from side to side

[The WidowMaker]

+1. the rear should not be offset. most drivetrains were offset, but that just required the pinion yoke being offset, not the axle flanges.

[DRJDVM's '69]

I'm doing some stuff with my rear suspension right now and am actually measuring for a new rearend...

On my stock rear the pinion is offset 1.5 inches to the pass side...in other words, measured from the pinion to the axle flange on the driver side its 32 inches...on the pass side its 29.5...so the pinion isnt dead center in the rearend side to side..... so the entire drivetrain is offset to the pass side alittle...

I think thats what you are talking about, or heard about......

Ideally the WHEELS/TIRES should have the exact same gap and BS on each side, but factory tolerances are often not that great and the mounts and springs arent in perfect spots to have that happen...so technically the entire rearend may be offset....but not by design or purpose

[amsterdam]

I got the same problem with my rear end; passenger side is 1/2" more inwards comparing to the driver side.
I can use a 1/2" wheelspacer to correct this so LH and RH are equal.
Or is there a way to shim the rear or adjust the shackles to get this done?

Erik

[amsterdam]

I got the same problem with my rear end; passenger side is 1/2" more inwards comparing to the driver side.
I can use a 1/2" wheelspacer to correct this so LH and RH are equal.
Or is there a way to shim the rear or adjust the shackles to get this done?

Erik

No one?
Should I try to shim the rear 1/4" to the passengerside or just use the 1/2" wheelspacer

Erik

[MrQuick]

I got the same problem with my rear end; passenger side is 1/2" more inwards comparing to the driver side.
I can use a 1/2" wheelspacer to correct this so LH and RH are equal.
Or is there a way to shim the rear or adjust the shackles to get this done?

Erik
nope, most likley in your perches.


vince

[amsterdam]

Oke. Thanks. I am gonna measure everything this week. The rear is a new one. It is a moser.

Erik