tire wear on inside rear

[Mr. Q]

damn, i hope not, lol. how do i check for that?
the wear on the left side was a few grades worse than the right side.
damn, i should've taken a picture. but then i'd cry again, so no bueno.

 

[Norm Peterson]

how do i check for that?

Ummm . . . measure your rear wheel cambers?

Find a level area to park your car on and lay a digital angle finder up against each rear wheel (at the flanges, not on the tires). Read the angle when the bubble is centered.

You can also use just a level and a small scale, plus a little trig to calculate the angle.

the wear on the left side was a few grades worse than the right side.

It is also possible that your rear toes are not zero either, with the left side being further out. Set up two strings that are parallel to each other and the car centerline, one on each side of the car. Measure to the wheel flange ahead of and behind the axle centerline about at axle centerline height. Toe out (which sounds likely) would be if the "front" measurements are smaller than the "rear" measurements.


There are ways of correcting these problems once you know by measurement what's going on, and DIY measurements are at least good enough to tell that much.




Norm

 

[fdjizm]

The axles have a natural angle from the factory for some camber, it's hard to notice but I think it's like 1 degree. let me see if I can find where I read that.

 

[19COBRA93]

Rear toe on the solid axle is supposed to be zero. There may be a very slight +/- on one side or the other or both because of manufacturing tolerances, but zero is the magic number. Much more than zero and it'll cause axle whine, and raise hell with the side/spider gears.

 

[fiveptohh]

I may have missed this, but is the car lowered? Inside wear is typical on cars with camber being out of range

 

[Norm Peterson]

REAR camber issues on a stick axle car are pretty rare, though.

-1° sounds more like an upper limit; I'd expect the vast majority of axle cambers to be under half a degree either side of zero. One of the limiting factors is the misalignment tolerance at the axle/side gear splines.


Norm

 

[19COBRA93]

I may have missed this, but is the car lowered? Inside wear is typical on cars with camber being out of range

On the front yes. Not the rear. Rear is "supposed" to be zero toe/camber no matter if the car is lowered or not.

 

[Norm Peterson]

"Supposed to be" and "really are" are two different animals. A really rough measurement of my Mustang looks like there's about a quarter degree negative on each rear wheel. The Malibu has about double that.

But lowering will of course have no effect on stick axle rear camber . . . whatever it happens to be is what it'd end up at after lowering.


Norm

 

[Mr. Q]

well, i knew there would be an extreme angle based on the wear of the tires. measuring them would tell me what I already know. what I was curious was, how do i check for bent axles?
i measured the angles, and i'm -2.7deg on the left and -2.3deg on the right. toe is zero.
i lifted the rear end up, started the car, threw it in first and watched the tires spin. there was no wobble.
i took the car to a couple places and they're all stumped lol. bent axles and possible blown wheel bearings/seals were the best suggestions, but i'm taking her to a local mustang shop and having them take a look next week.
thanks for the help norm and 19cobra93!

 

[19COBRA93]

well, i knew there would be an extreme angle based on the wear of the tires. measuring them would tell me what I already know. what I was curious was, how do i check for bent axles?
i measured the angles, and i'm -2.7deg on the left and -2.3deg on the right. toe is zero.
i lifted the rear end up, started the car, threw it in first and watched the tires spin. there was no wobble.
i took the car to a couple places and they're all stumped lol. bent axles and possible blown wheel bearings/seals were the best suggestions, but i'm taking her to a local mustang shop and having them take a look next week.
thanks for the help norm and 19cobra93!

You'd have wheel wobble with a bent axle. 2 1/2 degrees out is a LOT. In fact, damn near impossible. That's the type of negative camber the IRS guys dial in for racing. Let us know what you find.

 

[Mach2burnout]

You'd have wheel wobble with a bent axle. 2 1/2 degrees out is a LOT. In fact, damn near impossible. That's the type of negative camber the IRS guys dial in for racing. Let us know what you find.

No, its not impossible. A lot of circle track guys run camber and toe in solid axle rear ends. Asphalt guys run more than dirt cars but even on dirt there is usually a little. 2 1/2 degrees is a lot even extreme but not impossible and believe it or not the bearings, gears etc. will live a lot longer than you would think.

I measured mine in my 05 last Saturday night when I was setting my front end and it had -.5 degrees camber in both sides.

I would say that most rearends have a little camber, I know that ford and other manu. say the tolerance is almost 0 but every one I have ever measured had a little. Usually >-.5 degree. I have seen as much as -1.5 degrees camber in stock 9" ford rear ends.

 

[19COBRA93]

No, its not impossible. A lot of circle track guys run camber and toe in solid axle rear ends. Asphalt guys run more than dirt cars but even on dirt there is usually a little. 2 1/2 degrees is a lot even extreme but not impossible and believe it or not the bearings, gears etc. will live a lot longer than you would think.

I measured mine in my 05 last Saturday night when I was setting my front end and it had -.5 degrees camber in both sides.

I would say that most rearends have a little camber, I know that ford and other manu. say the tolerance is almost 0 but every one I have ever measured had a little. Usually >-.5 degree. I have seen as much as -1.5 degrees camber in stock 9" ford rear ends.

When I say impossible, I mean, his rearend would have to have been damaged, or modified on purpose to have that sort of negative camber. I don't doubt there is a small amount of camber/toe on OEM cars, but I'd suspect less than .5 degrees in even the more extreme cases.

A little quick math tells me to dial in 2.5 degrees of negative camber on the rear, each axle would have to have a rise of at least 1.25" from stock at the wheel flange compared with the side gears where the axle slides in the center section. So, either this car was jumped causing the axle tubes to be bent 1.25" upward on each side, or was modified by someone looking to dial in a LOT of negative camber on the rear. Both scenerios would cause a howl/whine from the rearend as the axle splines and side gears aren't rolling smoothly.

Slide an axle shaft in a carrier that's not in a rearend, and you'll be hard pressed to even get 1" of vertical movement.

So, not impossible, more like improbable.

 

[Mach2burnout]

When I say impossible, I mean, his rearend would have to have been damaged, or modified on purpose to have that sort of negative camber. I don't doubt there is a small amount of camber/toe on OEM cars, but I'd suspect less than .5 degrees in even the more extreme cases.

A little quick math tells me to dial in 2.5 degrees of negative camber on the rear, each axle would have to have a rise of at least 1.25" from stock at the wheel flange compared with the side gears where the axle slides in the center section. So, either this car was jumped causing the axle tubes to be bent 1.25" upward on each side, or was modified by someone looking to dial in a LOT of negative camber on the rear. Both scenerios would cause a howl/whine from the rearend as the axle splines and side gears aren't rolling smoothly.

Slide an axle shaft in a carrier that's not in a rearend, and you'll be hard pressed to even get 1" of vertical movement.

So, not impossible, more like improbable.

Oh, I agree. And was not challenging your knowledge, or intelligence. Just adding a little of my on from my personal experiences.

 

[Infamousjim]

... either this car was jumped causing the axle tubes to be bent 1.25" upward on each side...

I thought this too.... (though I think an axle would be one of the last things to bend if a car is jumped)

Mr Q, your car isn't orange with an 01 painted on the door is it?

 

[19COBRA93]

I thought this too.... (though I think an axle would be one of the last things to bend if a car is jumped)

Mr Q, your car isn't orange with an 01 painted on the door is it?

LOL, I was going to reference the Dukes of Hazard when I mentioned jumped, but figured I'd be the only one thinking it was funny.

 

[Mr. Q]

LOL, no, my car isn't orange with an 01 painted on the door!

ok, so i actually did the measurement incorrectly. i'm at -1.4deg on the left and -0.9 on the right.
i do have a serious howl coming from the back.

it turns out, i have bent axles. when i checked with the rear end up myself, i just threw it in first and watched for wobble, didn't see any. went to a shop, did the same thing, but under acceleration and there was definitely wobble.

so frustrated, i have no idea how i bent the axles.

 

[tjm73]

LOL, no, my car isn't orange with an 01 painted on the door!

ok, so i actually did the measurement incorrectly. i'm at -1.4deg on the left and -0.9 on the right.
i do have a serious howl coming from the back.

it turns out, i have bent axles. when i checked with the rear end up myself, i just threw it in first and watched for wobble, didn't see any. went to a shop, did the same thing, but under acceleration and there was definitely wobble.

so frustrated, i have no idea how i bent the axles.

Upgrade!!! Moser or others.....