ym42

Hello,
a couple of year ago I spun out on ice and hit a right curb. Lucky for me I was driving only about 30 mph, but the front suspension needed a lot of work. The estimate was about 3500$ as the front right fender was damaged by the wheel. The rear right tire also got some curb damage but seemed ok. I am noticing a considerably higher tire wear on the right rear tire, and I wonder if alignment might be an issue here. I took the car to the Firestone and they did the alignment, since the car was also pulling to the left ( a separate issue ). They fixed the front right wheel toe, and they gave me a print out where the actual values and the specified are shown and compared. Firestone shop fixed the front toe, but the front right camber is barely within the range. I have -1.4 when the acceptable range is 0 to -1.5. -1.4 out -1.5 is pretty close.
Should I ask them to fix that? Also, about the rear. The Camber is Toe is very different for the rear left and rear right wheel, but no range is specified.. Does it mean its not adjustable? What should I do about it?

rear left Camber 0.2 Toe 0.10
rear right ( the one I hit the curb with ) Camber -0.5 Toe -0.31 (!)
Cross Camber 0.7
Total Toe -0.21 (!)
Thrust angle 0.2 (!)


Advice anyone?

charliebrown266

I would say something is bent in the back! maybe the lower arm or diff! there are no adjustments for the back!

txminime

If you are talking about your '06 Mustang, it has a soild rear axle and should have close to 0 camber and 0 toe. Unfortunately, it is not adjustable. Your readings are suggesting the whole axle is tilting toward one side. Go to a frame shop and ask them to inspect your rear axle and rear subframe.

FC

Norm Peterson

Quote:

Originally Posted by ym42

a couple of year ago I spun out on ice and hit a right curb. Lucky for me I was driving only about 30 mph, but the front suspension needed a lot of work. The estimate was about 3500$ as the front right fender was damaged by the wheel. The rear right tire also got some curb damage but seemed ok. I am noticing a considerably higher tire wear on the right rear tire, and I wonder if alignment might be an issue here. I took the car to the Firestone and they did the alignment, since the car was also pulling to the left ( a separate issue ). They fixed the front right wheel toe, and they gave me a print out where the actual values and the specified are shown and compared. Firestone shop fixed the front toe, but the front right camber is barely within the range. I have -1.4 when the acceptable range is 0 to -1.5. -1.4 out -1.5 is pretty close.

What did the left front end up at for camber and toe? What are the caster readings?

Quote:

Also, about the rear. The Camber is Toe is very different for the rear left and rear right wheel, but no range is specified.. Does it mean its not adjustable? What should I do about it?

Rear camber and toe are not normally considered adjustable for a "stick axle" car (you have to physically "bend" the axle just a little somehow without screwing up the axle shafts or their splines' sliding fit in the diff side gears). But due to production tolerances and possibly even by design intent these angles may not be precisely zero and still be acceptable.

Quote:

rear left Camber 0.2 Toe 0.10

As mentioned, it sounds like either the axle isn't exactly horizontal for some reason or the alignment setup was a bit sloppy (keep in mind that the Firestone shops service the mass market with profit placed solidly ahead of technical excellence). It is at least reasonable for the total camber to be -0.3°, which is what the difference in your rear camber readings suggests. But that implies that the axle is about 0.35° out of level. This could occur if your rear tires were of different diameters for any reason - caused by any or all of the following (different size tires, different tire mfr or model, one new and one worn out tire, unequal rear tire inflation pressures, bent wheel, odd loading in the car while it is being aligned, even alignment rack errors or a bent frame). 0.35° is only 3/8" across the rear tires' 62" track, where in your case the right side of the axle is that much higher than the left side.

Your RR toe seems high (and "out"). An adjustable-length LCA would bring that back closer to zero and could be set to zero out your thrust angle (your left toe would get pushed slightly "out"). I think that you'd have about -0.10° on each rear wheel with a zero thrust angle, and that would most likely be better than what's there now. Understand that fixing this should help your tire wear but would probably make for a slight pull to the right.


Norm

ym42

Thanks Norm. I have to think about it more... I suspected that its possible to tweak a bit with the rear suspension, e. g. adjustable Panhard bar, LCA... I doubt my rear diff is screwed from slightly scraping the curb... my front specs now are:

L R
Camber -1 -1.4 (!)
Caster 7.1 7.2
Toe 0.07 0.05
Included angle 14.3 14.4
SAI 15.3 15.8

I would prefer my car to pull right, not left, for very obvious reasons of oncoming traffic :-)

Norm Peterson

You don't want too much tendency to drift right either. A good alignment tech will in some/many cases actually set the car to drift very mildly left just to keep the driver from having to consciously steer left to stay out of the gutter (and away from curbs!) on roads that have significant crown.


Norm

timothyrw

Why are the front camber specs so different? Is that acceptable?

Norm Peterson

Believe it or not, it is acceptable per Ford's generous tolerance. Cross-camber (side to side difference) can be up to 0.75° and they'll still call it "good enough". Part of the reason for this is that the FSM has to assume that the car is 100% the way it rolled off the assembly line and does not have any camber adjustment capability. So as long as it's within that "close", no further shop work is required and you get what you get.



ym - I have a feeling that something still may not be quite right up front, since the SAI and the cambers "differ" by about the same amount. A "tweaked" right side strut tower that got pushed in and wasn't pulled out all the way could explain it. It would only have to be off by a little over 1/8". I am assuming that you ended up with new strut(s) and at least a new right side knuckle (sometimes aka "spindle") and LCA.

If in fact that is the case, simply slotting the strut mount attachment bolt holes in the right side tower by 1/8" or so, making them longer going away from the engine (so that the right side tire stands up just a little straighter) should get you very close to having equal cambers and SAIs. You might or might not have to re-adjust toe.

That's if -1.4° camber is too much for your normal driving. If you're more hardcore about your average cornering than most folks, you could make other choices about your slotting.


Norm

ym42

The strut was replaced for sure, also the cradle ( thats what they told me but I have no way of knowing for sure now ), and surely the control arm since I saw it bent pretty badly. The wheel was pushed all the way into the rear of a fender ( towards the firewall ), the fender had to be replaced, whole thing made my wallet 3500$ lighter... ( I had no collision since I rarely drove the car and just did not see this ice accident coming, that was stupid of me... ) As far as my concerns over the alignment, it's not so much steering ( that was fixed with toe in adjustment ), but tire wear, especially on the rear axle...