LS4 Performance - rear alignment?

how come the rear wheels lean in at the top even when they are aligned properly? it just doesnt look or seem right. or are they not alligned correctly?

Hmmm, do the GXP's have some camber to their wheels???

the Impalas have some significant negative camber too.

yeah the weird part about that is its the inside of my tread is where i wore them to the belts it sucks will the dealer replace those you think im at 16K

I've own two W body's with different set of wheels on both and I've seen the same thing! (Lack of Better Words) I think this is just the way it is!!

alright thanks guys... kinda figured it was nothing.. didnt know tho cuz the tires have worn a little more to one side

Have your alignment checked. Gm runs pretty negative camber on all 4 corners on these cars. Negative camber and incorrect toe settings will eat the inside edges of your tires. Just have your alignment checked. A lotta times they will be out from the factory. When these cars are put together the alignment isn't checked on every one or any for that matter.

The negative camber wont wear out your tires as fast and incorrect toe will.

http://en.wikipedia.org/wiki/Camber_angle

2nd paragraph from link above:
Camber angle alters the handling qualities of a particular suspension design; in particular, negative camber improves grip when cornering. This is because it places the tire at a more optimal angle to the road, transmitting the forces through the vertical plane of the tire, rather than through a shear force across it. Another reason for negative camber is that a rubber tire tends to roll on itself while cornering. If the tire had zero camber, the inside edge of the contact patch would begin to lift off of the ground, thereby reducing the area of the contact patch. By applying negative camber, this effect is reduced, thereby maximizing the contact patch area. Note that this is only true for the outside tire during the turn; the inside tire would benefit most from positive camber.

To answer your question, the rear tires are supposed to tilt inwards to improve handling. Yes this can wear out the inside of the tire sooner than the outside, but sometimes sacrifices are necessary.

To answer your question, the rear tires are supposed to tilt inwards to improve handling. Yes this can wear out the inside of the tire sooner than the outside, but sometimes sacrifices are necessary.

Hmm..I wonder if this factory spec for GXP's. This is no good.

I just aligned my GXP at work on thursday. The spec for rear wheel camber is -1.15* +/- 0.70*

I just aligned my GXP at work on thursday. The spec for rear wheel camber is -1.15* +/- 0.70*

How do the rear tires look on your GXP now that it has been aligned?

I didn't have to touch the camber front or rear, they were within spec. The only thing I had to adjust was front and rear toe.

Toe is the biggest cause of rear tire wear on these cars, just so you know. Yeah camber tilts the tire and puts more weight on the inside of it, but incorrect toe makes the tire scrub as is rolls down the road which is where you get the majority of the tire wear from.

73k and no tire wear inside rears - ever!

73k and no tire wear inside rears - ever!

I don't think montes and impalas have the problem as much as the GXPs do.

I've never seen a monte or impala ss with rear tire wear issues, but non v8 impalas all the time.

The problem is that the rear toe is off such a subtle amount that it takes 15k+ miles to notice the tire wear. By that point you are out of warranty coverage for alignent or tires.

When I bought my 08 SS the rear toe was all fucked up. I did the alignment and it was out about .5 degree. It didn't even register on the bar graph on my alignment machine. They were pointed like this " \ / "

Maybe its supposed to help reduce understeer, lol

When I bought my 08 SS the rear toe was all fucked up. I did the alignment and it was out about .5 degree. It didn't even register on the bar graph on my alignment machine. They were pointed like this " \ / "

Oh great, now I need to check mine, I thought this was GXP only problems.

I just replaced the tires on my GXP 2 weeks ago. The rear insides were to the cords but the outsides were not quite to the wear indicators. I had the alignment checked and they said it was within spec so guess that is the way it is. My car did have 30k on it so guess it was time for new tires anyway. I just figured it would be the fronts to go first

On my stock height GXP I had to get a camber kit for the rear just to be able to align it properly. My fronts and rears chewed up the inside of the tires. The rears were still ok to ride on but the fronts needed to be replaced. I talked to the dealer about it and they never dealt with it apparently. :eyes: