When swapping my rims to put stock ones on for winter ( Dec) I noticed the insides of the rear tires had not only worn a lot more but also were scalloped. What causes scalloping/warping? The car was aligned in July, LF camber was -1.6, LR was -1.8, FT 0. RL camber -1.5, RR camber -1.7, RT .02. Rims had last been balanced in May. Normally ran 34-36 psi on these tires, 255/40/17, mounted on 17x9.5 rims.

 

Crap, wrong forum, mods could you move this to Tires, wheels, brakes, suspension?

 

negative camber will wear the inside of the tires. are you lowered? that will make things worse. the way your tires are sitting, according to those specs, is the top of the tire is in, and the inner edge is making the most contact. bad springs or shocks can cause that. how was the caster? that could be out and causing that wear too. any damage or accidents? just askin. good luck, i would get new tires and ease up on the camber a little. 0 toe is good.

 

are you rotating the tires?

 

Scalloping is usually caused by worn struts/shocks in a car. Inside/outside edge wear is usually caused by an alignment issue.

 

Thanks for the responses: Yes I rotate the tires, maybe not enough though. Just the rears where scalloped. Yes the car is lowered, It's a IX SE ( bought new 4 miles on it, never wrecked) I installed Swift springs/ Bilstien MR struts. I knew the camber would cause inside wear, just never had scalloping before. Struts feel fine, 37,000 mi. on car now, no noise, no leaks, still stiff. Caster is, left side 3.4 and right 3.5.

 

yeah i'm having the same problem. it's only the driver side that's cupping oddly. i'm lowered on swift spec-r's with mr blistiens - i can't figure out what's causing it at the moment, only speculations. i'm having the alignments recheck next week, your numbers are very close to what I had when i did the alignment after lowering the car

 

A: You have too much camber on the right side. You want to keep camber equal- fronts the same, and rears the same
B your caster seems ok- I try to keep less than a quarter lead on caster to the left, to compensate for road crown.
C: I would like to know what your toe is set to. With the specs you posted the inside of the fronts should not be fethering unless your toe is out
Hope this helps, I have not had the chance to align my car, still stock. I work on trucks and those are the general guidelines I stick to

 

Thanks GGMR06, I believe you are correct and that may be the issue. Struts seem fine, AND I'M AN IDIOT, when I put the rims back on today to my surprise it was the drivers side front and rear with the scalloping not both rears ( same as pao). Front toe was 0.00", the rear left toe was 0.02" and right rear toe was 0.01", total rear toe 0.03".