Let's talk centering a rearend.

[larry33kc]

Ok my rearend is a 1/4" to the passenger side to far and is rubbing.
I was told to take one of the upper control arms off and adjust the other to desired spec which I was trying to do.
Problem is I am out of adjustment on the driver side control arm , and still have a ways to go.

How do I go about doing this?

 

[Boost231]

You sure the body is sitting on the frame straight? Just wondering before you out your drive line in a twist

 

[larry33kc]

Yep. It's centered and is caged also.

 

[larry33kc]

Anyone

 

[John Larkin]

At this point I could only recommend checking basic geometry. Are the upper control arm mounts on the frame equidistant from each frame rail? Are the lower control arm mounts on the rear end equidistant from the ends of the housing?

You might consider also removing all the control arms and blocking the rear end where it sits centered in the frame and see how the control arms go into their mounts. Something may be bent or was assembled incorrectly when the car was produced. I bet GM had loose tolerances when they welded the differentials together since OEM specs did not need to consider close tire-to-frame clearances.

 

[pacecarta]

what you did was basically removed one arm (lets say pass side) and cranked the driverside in yes
if this was done on the ground what you did was crank the pinion angle down without moving the rear . on a lift the rear tends to just move over...all wheels on the ground it changes the pinion angle .
if you rotated the pinion back up to recommended angle the rear would have to move its position in the frame , put a jack under the front of the center section by the pinion yoke and if you raise it up the rear will move over but i would start with returning the arm you adjusted short back to original length and then put the jack under the pinion end

 

[larry33kc]

Well crap. Like the brilliant mechanic that I am I didn't measure the arm length.
Any ideas what the length is, also the pinion angle ?
I do have the jack stands on the axel. Pacecarta you have hit the nail on the head, that's how I did it.
So I should put the stands on the frame after I get it set back the way it was?
Thanks