rear fixed axle alignment question (with printout)

[friendly_jacek]

Hi,
I just had alignment checked on my daughter's 2003 Corolla. Firestone fixed front alignment problem (was it what caused tires worn in 20,000 miles or was it her heavy foot?). But they don't want to touch the rear axle, that is non adjustable.

Here is before:

and after:

Inspired by The Critic's thread on installing shims:
https://bobistheoilguy.com/forums/posts/2607616/
I'm planning to use the 0.5 degree shim from NAPA to fix the toe problem in RR wheel: http://www.napaonline.com/Catalog/Catalo...3056_0396294385

But, I have not done anything like this before. Can someone tell me I'm doing the right thing? Are these shims universal for most cars?

 

[Quest]

unless the car in-question had an accident before (this the rear's toe issues), why the right toe-in is off by so much? (on the rear)?

Q.

p.s. there are aftermarket shims and offset bolts to adjust camber, caster. Sometimes, rear toe on thise FWD can be adjusted at the cost of slight camber and castor offsets.

Q.

 

[friendly_jacek]

Originally Posted By: Quest
unless the car in-question had an accident before (this the rear's toe issues), why the right toe-in is off by so much? (on the rear)?


No accidents and no obvious/major damage to wheels, tires, or even hubcaps, but who knows about minor curbed incidents.

The alignment was supposedly good 20,000 miles ago when I gave the car to my kid, but I can't find that old printout.

 

[Rolla07]

I had my rolla aligned twice at the dealer in past 6 months. First to get it better, 2nd time cuz they replaced a wheel bearing. I have my sheet in the car, im curious how it compares. Toyota quoted me close to 400$ to do what they consider a proper alignment. Told them to forget about the shims and do basic alignment. I have no drivability issues so im not bothering. I could be wrong but it doesnt look too bad now. How does it drive? Sorry icant answer your question bout shims, no idea about doing it myself.

 

[Rolla07]

Ps. Im sure you can get a fast estimate at a dealer since you have the printout..if you might be temtped to check with them first.

 

[The Critic]

I responded to you over on Priuschat, but remember that the rear torsion beam assembly is "floating," so the amount of toe will change due to the toe-correction bushings that are in-use. If the total toe of the rear suspension is between the listed range, then no action should be taken.

One of the key procedures to a proper alignment on these cars is to center the rear torsion beam before alignment...there are posts about this on priuschat.

 

[kr_bitog]

You can get the SPC camber kit and rear shim to adjust to perfect alignment, however it is true the rear torsion beam need to be adjusted first before working on the front one.
Have you checked that all the shock absorber is in good working condition ?

I am sure the feeling of turning right and left is quite different on that setup, but if you do not feel it then may be just leave it until the irregular tyre wear or the suspension went bust.

 

[friendly_jacek]

Originally Posted By: The Critic
remember that the rear torsion beam assembly is "floating," so the amount of toe will change due to the toe-correction bushings that are in-use. If the total toe of the rear suspension is between the listed range, then no action should be taken.


Thanks for the info!

Total rear toe is -0.05 (average of 2 measurements) and it should be 0.20-0.60.

Not sure what impact that will have on the new tires I just installed. Fireston guys said minimal if any with regular rotations. The car drives OK, but not as centered as I would like.

This post seems indeed to suggest that rear toe out in FWD will produce some steering instability: http://www.focusfanatics.com/forum/showthread.php?t=143550

Thus, I'm tempted to goes ahead with the fix.

 

[Rand]

they will tell you anything to make you accept their "good enough" alignment instead of fixing it.

 

[friendly_jacek]

Here is one little problem. I looked and I have one shim already in the right rear wheel. It was fixed in the past due to out of specs camber and abnormal tire wear.
You can't stick 2 plastic shims together, right?
Then I don't know how to proceed short of removing the old shim and replacing with one that corrects both camber and toe.
If the old shim has 0.75 degree camber correction (according to paperwork I found) and I need 0.5 toe correction now, do I buy 1.25 degree shim and place it diagonally? Do they come with instructions?
Anyone with advice?

 

[The Critic]

Originally Posted By: friendly_jacek
Here is one little problem. I looked and I have one shim already in the right rear wheel. It was fixed in the past due to out of specs camber and abnormal tire wear.
You can't stuck 2 plastic shims, right?
Then I don't know how to proceed short of removing the old shim and replacing with one that corrects both camber and toe.
If the old shim had 0.75 degree camber correction (according to paperwark I found) and I need 0.5 toe correction now, do I buy 1.25 degree shim and place it diagonally? Do they come with instructions?
Anyone with advice?

You need to remove all shims and get a baseline reading of all alignment angles.

 

[Quest]

severe rear toe-out on FWD vehicles in most circumstances will not cause steering instability but more like abnormal tire wear (feathering of tire threads at an angle, while will lead to excessive tire roaring sounds as time goes by).

So long as your correct your thrust angle, your toe-in problem shall resolve itself nicely.

Q.

lastly: unless you are extremely knowledgeable on how to do wheel alignment red-neck style (been there, done that using 2x6 and strings), otherwise: it is still advisable to put them on the alignment jig and do it from there with the alignment machine "on". that way, you won't overdo things RE: shimming.

 

[CapriRacer]

What I am getting from the alignment sheets is that the rear axle is cocked. That is, it is NOT square to the vehicle frame.

I wonder if the frame is twisted.

It might be time to measure the vehicle to see if it is square. I know this will take some time and effort, but the current system of throwing tires at the problem isn't working - and the alignment shop doesn't seem to be interested in getting the alignment right.

 

[friendly_jacek]

Originally Posted By: CapriRacer
What I am getting from the alignment sheets is that the rear axle is cocked. That is, it is NOT square to the vehicle frame.

I wonder if the frame is twisted.

It might be time to measure the vehicle to see if it is square. I know this will take some time and effort, but the current system of throwing tires at the problem isn't working - and the alignment shop doesn't seem to be interested in getting the alignment right.


CapriRacer,
I have been explained by The Critic and some other people on Priuschat that the rear torsion axle pivots some and there is a special procedure to have it centered before alignment work.

Firestone didn't do it, they just took a 90 degree turn into an alignment bay.

The way I read it, there is a borderline camber problem on RL wheel and mild toe-out problem on RR wheel.

I will reevaluate it later to see if abnormal tire wear and/or if is getting worse.

 

[Ken2]

What is the total mileage on this 2003 car? How much wear is in the rear suspension bushings? Worn bushing and that right turn into the alignment bay may be just taking up part of the slack in worn bushing.

I'd have it check in a good frame and alignment specialty shop. A good tech in a Firestone shop can do an OK job on a car with no problems. A car with problems such as worn parts or bent parts needs a shop with more knowledgeable techs.

 

[edwardh1]

dealers used to have 3 ranges of alignment specs
one was warranty work
one was customer paid work
cant remember the other maybe it was dealer paid alignments

 

[friendly_jacek]

Originally Posted By: Ken2
What is the total mileage on this 2003 car? How much wear is in the rear suspension bushings?


91,000 miles of mostly city driving. No accidents. Not sure of suspension wear, but doubt it.

 

[eljefino]

Originally Posted By: Rand
they will tell you anything to make you accept their "good enough" alignment instead of fixing it.


Righto, did they advertise it as a 4 wheel alignment or didn't they?

Then there's the small print, extra parts are extra. If you need shims, that's an extra part.

 

[friendly_jacek]

New development:
I watched youtube for DIY alignment with string, did it myself TWICE after moving the car in between, got the very same results, and the Firestone alignment is wrong!

String results (toe only):
FL: +4/32 or +0.34 degrees
FR: 0
RL: +4/32 or +0.34 degrees
RR: 0

Now that remember the alignment process at Firestone, I don't remember the guy taking wheel covers off at any time. I didn't look all the time though. Could he be so stupid to take measurements with wheel covers on?

Time to take it to another shop.

 

[friendly_jacek]

Originally Posted By: friendly_jacek

Time to take it to another shop.


I took it to another Firestone and front toe in was wrong indeed. I've got that fixed. The rear showed the same numbers though. Since the total toe is essentially zero in the rear, I'm not going to fool with it now.