Are GM rearends notoriously not centered?

[fultz1275]

I just installed a new rearend in my 68 chevelle. it is offset to the passanger side by about 1/8". I called DSE to ask them the best way to center the rearend considering im using their upper and lower control arms. They said the GM rears are rarely centered and there is typically less tire clearence on one side verses the other. They said not to worry about getting it perfectly centered. Can anyone confirm this to be the case with GM rearends? Should I expect to have it offset to the passenger side by about an 1/8 inch.

[SLO_Z28]

Yes, they are. Even the new vehicles are that way. Its not unheard of to have a rear end 3/4's of an inch off center in a GM muscle car.

[Autokraft]

Slo-Z is right. It is common to see them off center

[intocarss]

Yup mine is over to the right.,.Drives me nutz

[WILWAXU]

Yup.. I had to go with a 1.5" spacer on the drivers side and a 1" spacer on the passenger side to get 275/40 17's on the back of my Nova.

http://www.fquick.com/images/vehicles/full/21942198981.jpg (http://www.fquick.com/garages/viewgallery.php?action=viewimg&id=198981)

[214Chevy]

Yep, drove me nuts too. I had a 12 bolt that was off center to the right and my right, rear wheel was closer to the lip on the quarter panel than the left was.

[drc270]

My 12 bolt is off 1/4" also. I am getting ready to pull it and have it rebuilt.
My plan is to remove and replace leaf perches accordingly to center the
housing. Is this the best way to correct issue?

[fultz1275]

Thanks for all the feedback guys. :thumbsup:

[The WidowMaker]

it may be more than just the rear if you have a full frame car. my body properly aligned sat 1/4" closer to the frame on one side than the other. frame checked out on all measuerments, but they allowed for a lot of "slop".

[LUACE]

this just makes things more complicated. I am about to narrow my rear end. Should i not narrow 3 inches on both sides? is there a chance I may need 3 inches on one side a 2 3/4" on the other, to get it properly centered? what would be the proper way?

[Track Junky]

The proper way would be to plumb bob down from all the mounting points on the underside of the body and fix anything out of square or out of line.

Then measure all mounting points on the rear end and be sure they are equal at all attatchment points on both sides.

[67zo6Camaro]

The proper way would be to plumb bob down from all the mounting points on the underside of the body and fix anything out of square or out of line.

Then measure all mounting points on the rear end and be sure they are equal at all attatchment points on both sides.

Agreed here. Most GM cars I have crawled under have about a 1/2" off-set in the drive shaft tunnel allowing for the rear pinion yoke to be about 1/2" off-set to the driver side.

If you are going to do any modifications to the rear end including suspension this is the time to center the drive-shaft and pinion yoke to the off-set possition (centered in the drive-shaft tunnel) then build every thing to the squared position. It typically ends up with 1/2" wider axel on the passenger side to compensate.

My 9" rear end set up has the drive-shaft and pinion yoke that are centered to the 1/2" off-set in the tunnel to one side and then my rear end axel is 1/2" longer on the passenger side (opposite side).

Square everything up to the frame and suspension mounting points, not the body lines. That way the importance is focused on the tire contact patch being true and square. Once the suspension is true, then you can adjust body panels for the proper look and proportions.

Sorry long 2cents here.

[DETON8R]

I'm running a ford 9 inch from a 67-69 Mustang/Cougar in DETONATOR and it was offset to the drivers side. When I got the Chris Alston's weldment bracket for the two upper links for the g-link they actually had a set of index holes for 0" and 1/2" offsets. Of course mine was somewhere in the middle so the shop that welded up the brackets had to slot the hole between the offsets to get it dead nuts in the middle of the housing.