mtksurfj

Heya! Was measuring my brake calipers today (don't ask) and I noticed BOTH rear tires (PS2) are worn to the cords and wires on the inside 2"!

Is this a telltale of a problem with my toe settings? Had it aligned before my last track excursion... guess I'll get it aligned again. Perhaps throw on new toe links?

Thanks!

-Ross

fhp911

sounds like a classic case of too much negative camber. a *very* aggressive (over aggressive) alignment.

can there be other explanations? Toe mis-adjustment would cause other weird tire wear.

ron_dargenio

I guess excessive toe could cause that, but the most obvious cause would be too much negative camber. You can probably eyeball this; but in any case when it goes onto the alignment rack, you will know for sure. Since you need new tires you might as well get it all done at once.

NJ-GT

How many track/street miles on them? They always cord on the inside first when the car is driven on the streets, even with the stock alignment.

Rob in VA

How much negative camber are you running at the rear?

Austin

Yes, classic case of the camber and/or toe scenario.

Sounds like rear toe arm bushings and/or thrust arm connection bushings (on control arm) are failing. During braking, your busings are stretching and causing toe out. The entire wheel carrier moves around from the rubber flex from all the attachment points to the unibody. I recommend the usual suspects, upper monoballs, and toe arms with monoball attachment to subframe. There are multiple benefits (including better tire wear) and no additional road noise or harshness.

Austin

Supermonkey

It's the nature of the beast...they all do it even when set up to factory alignment specs. How many mile did you get out of these rears? You can probably count on replacing the rears twice as often as the fronts.

mtksurfj

8k on these rear tires... might be 10k depending on what the first owner did... so I'm not feeling cheated, that's plenty of miles. 4 track days at the glen and 2 at VIR. Toe was .28/.09 (Rr/Lr) and camber was -1.8/-1.8 (Rr/Lr). I'm going to dial out some of that negative camber today during alignment.

Marv

I think that is normal for factory settings.

AudiOn19s

As already stated it's pretty normal for a car that sees both street and track miles and has a compromise camber setup like yours (or the factory settings for that matter)

Too many street miles and you'll cord the insides first

Too many track miles and you'll wear out the outsides first.

Your solution is easy...More track days.

Andy

RJFabCab

10K miles on your rears... including track time??? Call it a day and get another set... you're lucky they lasted so long.

RE your alignment, I wouldn't dial out any more negative camber. You're only running -1.8 out back and that's nothing. Your toe settings seem appropriate, although I'd have them evened out side to side.

You burned out the inside edges with minimal neg camber and reasonable toe settings... AND you got 10K miles out of the set. It sounds like there were a lot of street miles on those tires.

With only -1.8 camber in the rear with lots of track miles your outside edges would be TOAST. However, Austin's comments about dynamic toe changes are surely something to consider!

If you mostly street, I'd keep the alignment just about right where you have it.

DanH

You can also get this problem from running too little air in the tyres. Particularly common coming away from a trackday where you've let 10psi out as they are running hot, then driving away without replacing that 10psi so that as they cool on the road they run heavily underinflated and do that. Pretty dangerous...

ron_dargenio

+1