What would cause my 315s to wear signifigantly more on the inside?

[v7guy]

Have my back wheels off and the insides of the tires are worn way more than the outside.
Could they be hitting the fenderwells and not be leaving any signs that they are?
Axle bearings?
Anyone else have this problem?
The car is a 94 firebird, rear has 100,000 miles on it.
I take it to the strip every other weekend and drive pretty aggressivly all around?

[Norm Peterson]

If your axle has bent slightly you could have either a little toe or some negative camber. Or both.

Given your 315's, I suspect that you have a little negative camber back there rather than toe-out, perhaps 1/2 degree or so. That's where my '79 Malibu (also with the 7.5"/7.625" rear) is after 23+ years. Many years ago it was only -1/4 degree, so it's something that tends to increase with age and hard use.

Norm

[This message has been edited by Norm Peterson (edited July 01, 2002).]

[v7guy]

Thanks alot, I appreciate the response, I have plans to replace the rear with a 12 bolt in the next 6-9mo, I'm assuming the axles would be fine until then?

[Norm Peterson]

It's commonly assumed that rear axles are "perfect" - with zero camber and toe. But due to various tolerances and the fact that the axle bends slightly under load this is often not the case.

Your axle shafts and side gears will probably tolerate a whole degree or a little more of combined camber and toe per side almost indefinitely. Note that this total angle is not the straight addition of camber & toe; it's Pythagoras' theorem (right triangles and geometry class). What I'd do at this point would be to measure the camber and the toe of both rear wheels. If you have a level driveway you can do this yourself instead of trying to explain that you don't want a rear wheel alignment for a stick axle, only the measurements there.

If you're still worried (and particularly if this car has seen lots of dragstrip duty) you might want to check the condition of the splines.

Norm