yes a bad tire can affect the alignment but moreso when the car is moving as the wheels are aligned not the tires so if you align the wheels and the tire is worn the car may still pull or drift because of tire wear.

new tires remove the problem caused by the bad wear pattern ..then if you still have an issue it isn't a tire problem but something else

and the wheels are not off the ground they are on the alignment rack with the full weight of the vehicle...the pads below the tires will move to allow adjustments

 

One of the really huge problems with shops that do alignments is that they depend totally on the computer doing the work. Any modern-ish alignment system is programmed with all sorts of stupid little programs that allow a 'tech' to get all the numbers 'in the green'.

There are very few true ALIGNMENT TECHNICIANS who understand exactly what all the angles and measurements are.

I know this because I consider myself to be more than qualified to align any vehicle with over 20 years of experience working on cars for a living. It drives me bat-**** crazy to see this happen over and over again. A customer will have had their vehicle aligned where they bought tires and now it drifts or pulls. Once it's on the alignment rack, it's no wonder it pulls.

This is one of the many reasons I love Corvettes. EVERYTHING is adjustable as far as the alignment is concerned and there is a LOT of travel in the adjusters.

okay, rant over

 

I stand corrected.

 

Yessir!

 

?????



The tires are most certainly sitting on the "turn plates" in the front, and the "sliders" in the rear, as it sits on the alignment rack. You cannot align a car unless the suspension is "loaded" with the springs and shocks at normal compression.

 

Gotcha! Like I said, I stand corrected.

 

I feel the same way... I have been working on cars for years and now teach auto tech... I like the cars where everything is adjustable... you can make the car drive perfect.... my c5 drives straight as an arrow...

 

So then where do you and Tommie stand on the statement that if a is car aligned with a bad tire (like a slipped belt) it can affect the alignment and throw it off?

 

if a car is aligned with a bad tire (tire is not round, bad belt etc) and the tire is in just the right spot, i believe it could throw the alignment numbers off.... (but i think if a tire was that bad you would feel the vibration when driving)

Most of the time when you are doing an alignment it is for one of the following reasons:

new tires...

normal maintenance....

vehicle is pulling/drifting etc....

The first 2 are the easiest alignments to normally do.... if the car is not pulling or drifting when i let go of the wheel the adjustments necessary to the car should be minimum....

If the car is pulling or drifting to the right or the left, it is either caused by a tire pull or by an alignment pull....

After a test drive to verify the customer's complaint....

I normally start with the tires, I have a Hunter road force balancer with straight track.... this type of balancer allows me to balance the tires, check for excessive road force on the tire, determine if the rim is bent or not, and determine if the tire can be phased matched with the wheel to reduce the overall roadforce, or if the tire needs to be replaced.... The straight track feature also determines the amount of pull that a tire can have on a car and will suggest the correct placement of the tire on the vehicle to reduce pull (this does not work on the c5 due to staggered tire size and directional tires)....

After the balance, I will perform another test drive to see if there were any improvements.... On a car with all 4 rims and tires that are the same size and not directional (not the c5) it may be necessary to do some additional tire rotations (if you are not using the balancer that i mentioned with straight track)..... if a car pulls to the right I would cross rotate the front 2 tires (swap left front for right front) and take another test drive... if the car pulls left now, you have a tire pull issue with the front 2 tires and they need to be replaced... if the pull is still right, i would swap the left front tire with the left rear.... or swap the rears to the front and cross them... most tire pull issues i have had were with the front 2 tires... i have only seen a few that were traced to the rear 2 tires.....

once the tires are sorted out, i would move to the alignment.... this is easy on the C5.... all of the adjustments are easy to get to.... you start with the rear camber then the rear toe..... then you move to the front adjustments.... front camber and caster, then front toe....

toe wears tires the most and does not generally cause a pull....

camber wears tires the second most and will pull to the side that is more positive .... if the left front is -.7 deg and the right front is -.2 deg... the car would pull to the right....

caster does not wear tires... caster pulls to the side that is more negative... if left front caster is 4.8 deg and right front is 3.8 then it would pull to the right.....

i try to adjust the front caster to reduce vehicle drift or pull or to compensate for road crown....

damn.. i hate to type that much... hope it sounds right....

 

Makes perfect sense, thank you.

However, I just had a bad tire causing a pull. There was no visible defects to it and it did not vibrate or anything. I had the alignment checked and it was fine, but had a good pull to the right. The tires were new from Tire Rack. I called Tire Rack and they promptly sent out a new tire, even credited me $25 for the remount and balance.

Put it on and the pull was gone.

I really have to give kudos to Tire Rack. I figured they'd give me a hard time, they didn't at all. Even paid shipping both ways. I just said that the alignment was ok and the tech said it must be a bad tire. They sent it right out.

 

that's cool that they sent a new tire.... I have bought new from discount before and performed a road force test on them when I balanced them and had new tires with excessive road force.... took them back and swapped them out... Had this happen on 1 with my daily driver beater....

 

Sounds like BS to me. All the aligment tools I've seen clamp to the rim or wheel, not the tire or the rubber part. So, I'm not sure how a drivable defect in a tire could throw off the machine when it not measuring where it could be affected by the faulty rubber.

 

the only way a bad tire could effect the alignment would be if the tire had a bad belt or was out of round..... this should be noticeable when driving the vehicle......

basically if the tire was not round...... it could throw off the alignment measurements....

 

How? I've never seen any alignment equipment that uses the tire to measure.

 

I think he means while driving...not sure though

 

However, "in the green" falls within the "specified range" in the shop manual....


It helps eliminate labor "charge backs" on warranty claims.

 

lots of tweaking and it is finally good to go....Mike and his guy spent 3 hours making adjustments and letting me drive it.

I honestly think this car does not like these tires (KDWs)...I have them on my 99 with no issues but they haven't been quite right since we put them on her 02 ...we only made the change since Toyo stopped making the ones she had. I was honestly ready to take them off buy 4 new tires different brand and start over

apparently a Google search will bring up several topics dealing with the same issue.

 

I'm really happy with my Continental Extreme Contact tires, very comparable to the Michelin Sports but at half the price.

 

Agreed. The ExtremeContact DW's that I bought a year and a half ago are still going strong; way more traction than my old Toyo Proxes T1Rs (they were probably old and hard, came with the car) and good treadwear so far also.

EDIT: ExtremeContact DW's is supposed to be read as a plural of DW, not the ExtremeContact DWS which is an all-season tire. I wouldn't run all-seasons on any Corvette; get dedicated summer and winter rubber. I run Blizzaks when the temperature drops below the mid 40's.

 

I did not read all of the posts so i am sorry if this is repeating. Most people now a days dont know how to perform a proper alignment. they look at a computer screen like zombies and just Set it so the numbers are green. this is so wrong and results in problems like yours.

Luckily i learned how to align from my old man who learned correctly.

It is all about the numbers, Easy thing to remember is that camber pulls positive and caster pulls negative. the variance on a normal car is about .5 which is a lot. toe will NEVER cause a pull just wear unevenly, and cause your steering wheel to be off center. and also there sould be about .5 degree less caster on the left then right, this is put in there to compensate for road crown.

For example:
Left Right
camber -.9 -.6
caster 3.5 3.6

This will read all green and within spec so it is all good right?
WRONG, this car will definatly pull to the right, if you got a printout of the specs from your alignment which a good shop should give, post it so i can see it, thanks hope it all works out for you.