ChrisSingh90

iTrader: (12)

Hey guys, quick question for you all. I had stock wheels and tires on my WS6, but had new ones ready to go on. In preparation for the 315/30/18 rear wheels, I bought an adjustable panhard bar.

I installed the panhard bar with the factory wheels, and measured the distance from both side fenders to the tires. I then adjusted the panhard bar until the measured distance on both sides were equal (AKA diff is centered).

Anyways, I installed the 18x10.5 wheels in the rear with the Toyo 315/30/18 R888's, and the driver's side is rubbing the inner fender, just going straight.

My question is, do I uncenter the diff to move it over and stop the rubbing. Or should I just hammer in that section and keep the diff centered? I'd like to keep the diff centered so I was planning on going that route.

Is there a more accurate way of centering the diff? Part of me feels like using the fenders isn't accurate. Can alignment machines make these measurements? If so I'll take it to have it aligned so they can align the diff perfectly, then Ill clearance what I have to to make the wheels/tires fit.

Chris,

camarokid91

With 315's in the rear you typically have to hammer in your wheel wells. Also keep in mind the rearend will shift when cornering to a certain side. 50mm to 32mm offset wheels will work in the back. My suggestion would be to keep it centered and get a hammer and truck bedliner and clearance your inner wheel wells.

ChrisSingh90

iTrader: (12)

I hammered in the bottom of the inner wheel well, that inner bottom "lip" so-to-speak. It's perfect now! Diff is as centered as I could get it, it's 1/16" off to the right side but I don't think I can get any better than that! No rubbing at all, on turns or bumps.

Tires/wheels look awesome, will try to get some pics up. These R888's hook like crazy even in these wet salty roads. I think I'm gonna have a heart attack though, going home and washing the car and putting it back into hibernation! I did get to have my speed fix though haha.

Chris,

1 FMF

iTrader: (1)

when you change the length of the panhard bar and move the axle left or right, you alter the thrust angle and also the drive shaft u-joint operating angle. the thrust angle of the rear axle should be 0°, so the car goes straight down the highway and doesn't crab. an alignment shop that can do 4 wheel alignments can measure thrust angle. you have to specifically request that since you have a solid rear axle, shops won't even think of doing it unless you request it because normally there is never a need to check it.
doing the math based on a 50" length from the axle to the front u-joint at the transmission, moving a 1/2 inch is about 1/2 degree change in drive shaft and u-joint angle. you move it more than that and I think you risk alignment issues, and vibration from increased u-joint operating angle and also having the front and rear u-joints not phased. then you require adjustable LCA's to correct thrust angle.