Alignment Question for C4C5

Well I finnaly went from GY to Michelin Pilot/sport A/S ZP. Yes they are very quite but I have not tested the grip yet. My concern is that after they were installed the car pulled to the right real bad. I went the next day for an alignment. Well after the first try it still pulled right. Went back 3 days later and they re-aligned and it still pulled. Now this is a GY dealer and they said that it is either because I am not using OEM tires or there is a radial pull problem. I went back to Disc. Tire and they put on a new right front tire. I drove for a week and it still pulls. Went back to Disc. Tire and they put on another right front. Yes you guessed it it still pulls right. Now the guy's at Disc.Tire say that sometimes they see radial pulls but very seldom 3 tires in a row. I aslo do not see that switching to Michelins are the problem. I am going to post the alignment numbers to see what C4C5 thinks. I do not understand the numbers but here they are:

First alignment:

LF; Camber -0.4 RF: Camber -.05
Caster 7.3 Caster 7.1
Toe 0.08 Toe -.05

Total toe = 0.03
Steer ahead 0.06

LR: camber -.01 RR: camber 0.0
Toe -.02 toe -.05

Total Toe = -.06
Thrust angle 0.01

Second alignment:

LF: Camber -.02 RF: Camber -.02
Caster 7.4 Caster 7.5
Toe 0.04 Toe 0.04
Total toe= 0.08
Steer ahead = 0.00

LR: Camber -.02 RR: Camber 0.2
Toe 0.02 Toe 0.1

Total toe= 0.11
Thrust angle = -.04

I hope someone can spot a problem here. Thanks in advance and SAVE THE WAVE !

[JonM]

http://www.vettebrakes.com/align.htm

[fhturner]

Could it have anything to do with the crown of the road exaggerating the problem? I seem to recall when I had my '98 aligned that the alignment tech/specialist left a bit more caster on one side than the other. I believe it was something like 0.5° or 1°. He said they usually do it that way to compensate for the normal crown of the road. It sounds like your problem is more pronounced than that, but you might see what happens if you cut back the caster on one side (I think it was less on the left front when they did mine)... Sorry, I know that's not much help, but maybe you can make some use of it!

Good luck,
Fred

[c4c5specialist]

Hi there,
Well, I am not trying to be funny, however, are all tire pressures at 30psi?????
If so, then we can proceed.
I do not see a very critical alignment spec, SAI or steering axis inclination. This could tell us additional information. Do you have that on the printout?????
Also, please look to see if you have 'Included Angle' on the printout.
The specs that you have show, are very close, and right on the money. I would be very pleased with those readings. However, there may be something under the surface that is not being shown here.
I would also suggest that you cross rotate the tires, simply to see if the pull goes the other way.
And I am also including the rears in my recommendation.
Honestly, I think it may be coming from the rears.
Please keep us posted, c4c5

Yes all tires are at 30psi, sorry. All the numbers are from the print out . I do not see "steering axis inclination" just what they call "Steer ahead" which is at 0.00. I do not have "included angle" just "thrust angle" on the rear which is -.04. It is very interesting that you mentioned the problem might be the rear. Disc. Tire thought for sure it would be the front right tire. Since you are saying my alignment numbers are right on, are you leaning more towards the radial pull theory but on the rear tires? I will see about getting the rear tires swaped to see what happens. Also for Fred I thought about that also so I found some flat street and it pulls real hard to the right . I also found a road that leans way to the left and the car drives straight on that. Thanks for all your help C4C5 and all the replies.

Yes I am back to my original user name thanks to Rob. I lost every thing else after my computer crash and e-mail adress change. Sorry for the confusion on this thread.

[c4c5specialist]

HI there,
Yes, i would not leave anything to chance.
Anything can be possible.
As for the rest, well, I am sure you are being taken care of.
Please keep us posted, c4c5

[raycdosu]

WOW! When I saw this post, at first I thought it was a post that I submitted over a year ago. I had the exact same problem with the Michelin Pilot Sport A/S, and I took it to several different places for alignments, all with the same results. The switched the sides of the tires, changed the tires completely (twice) to no avail. It continued to drift right. Everyone said I was crazy and that there must be a mechanical problem with the vehicle (wrecked, damaged, etc.) that was causing the alignment, not the tires. But I knew otherwise, because it handled perfectly until I got the new tires.

To make a long story short, I told them to get rid of the Michelins and put the Goodyear EMT's on. Needless to say, it drove straight down the road after that.

I think there's an issue with the Pilot Sport A/S on a vette.

[VetNutz]

I just switched over to Michelin ZPs and am having the same problem discussed here. I've gone through the same resolution process as well: checked the air pressure, had another 4-wheel alignment, and replaced the right front tire. Still have the same problem with it pulling to the right. The Michelin rep now suggests we replace the LEFT front with the tire originally mounted on the right front to see if that cures the problem. In other words, nobody knows what's causing the problem, and are guessing at a solution. The tire dealer is caught in the middle and bending over backwards to help me out with a resolution. I'd rather not waste any more time and effort with the trial and error approach. Does anyone have an update on this?

I am still pulling to the right. VetNuz when you switch the front tires post the results. I have not persued it myself because of time restraints.

[atmmac]

Michelin is a french company what did you expect?

[vettepilot]

Yes, They are French... therefore one would think that Michelins would pull more left than right.

vettepilot

[Hib Halverson]

I take it, the car in question has had at least one of the Michelins on the front, changed-out.

I'd swap the rears and see what happens. Also, while you have the rears off, measure the circumference to see if the Michelins are so bad they have some stagger.

I'm surprised we have three different people complaining of a similar problem with the same type of Michelin tire.

Sheesh...I'm glad I decided on Goodyear F1 GS-D3s over Pilot Sports.

[froggy47]

GY Gsc's with VBP alignment in between adv street & autox baseline. SOB tracks like an arrow.

I would say forget the crown of the road bs with a vette.

Viva la USA.

[VetNutz]

Thank you, everyone, for the quick response and helpful suggestions.

Hib, I read your review on the GSD3s and had them deliver a set along with the Michelins. Made my decision based on the run flat and all season capability. I will take your suggestion and measure the rears before swapping the remaining left front. I originally ingored the rears because the car does not pull any worse under power than when coasting. Thank you.

This is my daily dirver, and I do drive it A LOT. Last summer made trips from Virginia to upstate N. Y. a month later out to New Mexico, and a couple trips to western Tennessee. The stock Goodyears gave me 30k and my main complaint was the noise. The Michelins are quieter and ride better. I'll be happy if I can just get this thing to keep pointing straight ahead; it'll make the trips much more enjoyable. I'll post an update if the problem gets resolved.