Differential Position

[Jeff Rand]

Just finished installing LCA (HRParts 1/4" longer then stock) and I noticed that my driver side slick is even with the rear fender and the passenger side slick is about 3/4" out from the fender. The driver side has been contacting the frame and a spacer would be required the get the clearance needed. It might have always been this way and I never noticed it. Is this common for G body cars? The longer control arms do center the tire in the wheel well.
Thanks,
Jeff

 

[Glen]

There is a SLIGHT difference, left to right of the wheels. This is due to the shimming of the carrier, to obtain proper backlash, in a 10 or 12 bolt rear, when using 'C' clips to retain the axles. This can be compounded by ring gear thickness and/or aftermarket carriers, or the wrong combination of ring gear and carrier. That is why there are different carrier series. This is, of course, dependent on the fact that the rear itself is centered. And then, there is what is called stacking.That is when you have an offset of say 1" on one end, by the time you get to the other end, and it doesn't matter how far, that offset has grown to more than an inch, go fig'r.

 

[Jeff Rand]

Glen, I never thought about shims on the carrier . At the same time that I did the LCA I also relpaced the 3.90's with 3.42's and I did have a to add shims on on side to get the proper backlash. So is that just the nature of the beast or is there a fix.
Thanks,
Jeff

 

[Glen]

It is a two headed beast. Your talking about 3/4 of an inch, thats alot. I'd be looking at the ring gear thickness. Is the carrier right for the gear ratio? I would have to look, and maybe someone has the info in front of them, BUT, I believe the carrier is different between a 3.42 and a 3.73. I BELIEVE, but don't hold me to it w/o checking, but a 3.42 is a 2 series carrier, while a 3.73 requires a 3 series, in most cases, but it might be a 3.23 is the limit for a 2 series carrier. Now, some ratio's can be purchased to mix the two. What they do is make a thicker ring gear.

But anyway, if you have a boat load of shims on the left side of the carrier relative to the right side, effectively moving the carrier to the right, I would start there.

 

[Night Train]

I would also check backspacing on the wheels, especially if they are aftermarket. My son ordered a set from Summit once and they shipped two different backspacings for the rears. He never checked before he mounted his slicks and always wondered why slicks stuck out about 1/2" further on one side.

 

[Jeff Rand]

Night train, very good point. I just reinstalled the slicks on the car and I reversed the tires and rims from the normal position. I will check the backspacing tonight.
Thanks,
Jeff