Saab pulls to left, rotate tires, pulls to right

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We bought a used 2008 Saab 9-3 2.0 about a year and a half ago. When we bought the car it pulled to the left pretty strong, but only at speeds over 65 or 70. To notice any pull under that speed you really have to be looking for it. I had the alignment done (twice) and the print out said all was fine there, and then gave in and got 4 new tires for it. It still pulled to the left.

So a few weeks back I had the tires rotated. Now it pulls to the right, exact same symptoms as before, just to the other side. I am wondering if this is related to the shape of a wheel (or two). They appear to be fine. There is a scratch on the side of one but nothing major. Is this possible? Any other ideas?
 
It could be a bad wheel, I would have said tire but I'm pretty sure you ruled that out by replacing the tires. Does it do the same thing when you move the rear tires to the front of the car? That would be a good way to check.
 
Did you have your tires rotated in the normal fashion or, were the two front tires swapped with one another?

If the two front tires were swapped with one another, then there is the possibility of a rim/wheel being the cause of your pulling. But, I would have to blame the tires as I have had more than my share of "Radial Pull" with many brands of tires, especially G/Y.

You also mentioned that you have installed NEW tires! Do you know if the wheels were installed at the same corners of the car as when they were removed?

Process of elimination: You have already done the Alignments and have at least moved the tires at different corners of the car.

You'll find the cause I'm sure! A little more work on your part to narrow down the culprit.
 
Simple test:

Swap the front tires left to right:

If the pull completely changes direction, then the problem is 100% in the tires - a property called conicity.

If the pull doesn't chnage, then the problem is 100% in the vehicle - most likely alignment. My opinion is that the published alignment specs are too wide by half. Put another way, the values have to be within the inner half of the tolerance.

If the pull changes - other than a 100% reverseal, then the problem is both tires and vehicle.

The fact that you "rotated tires" and the the pull changed direction, would tend to support the tire only proposition.

So perform the test and see what happens - and if the pull changes direction, then swap ONE of the front tires with one of the rears and see what happens.

What matters in this case is the vector sum of the conicity. Paring certain tires in a set of 4 can develop high net conicity values, but pairing different tires within that same set can result in low conicity vales. It's the pairing that is important, not the inidividual tires.
 
Radial pull. Quite common actually. Keep rotating until you find a combo that doesn't pull. Put the rears in the mix. Mark the tires with chalk and number them so you can remember what combo worked/didn't work.
 
If a tire was smaller in diameter, different make, much more worn more than the others, it would have more or less rotations than the other tires causing a pull that would be noticed more at higher speeds. Are the tires a matched set? Is the suspect tire worn down compared to the others? Same make?
 
Ok, will experiment with rotating the tires. I wasn't expecting the last tire rotation to change the pull, and had this done at a shop so I don't know what they rotated where. That should isolate it further (hopefully) and from there determine tire or wheel. It would be fantastic to get to the bottom of this. The tires are Goodyear Eagle GT... have the same type on a BMW 3 series and they have been good on that car.
 
Shuffling the tires around will almost certainly get you to where you want to be. It's also a lot of work. You say you bought the tires just a few weeks ago so that may not be necessary.

All new tires have some sort of warranty. If you contact the vendor or the manufacturer they should remedy the problem for you. How they handle this sort of thing varies. Typically Michelin and their lot or Kumho would send you to an "authorised dealer" to have pull measured on a balancer, then, if suitable axle pairings are found to be doable, they'll position the tires to eliminate pull and make it so pull stays gone with regular rotation. Firestone will usually just want to very that there's a tire pull and throw a new set on for you.
 
I'm not certain what could happen to a wheel to cause a pull. A improperly positioned belt would. A bent rim will cause a wobble, not a pull. Just think about the geometry of the wheel/hub... how c ould you bend that to cause a pull without a wobble. BTW the defective tire could be on the back.
 
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A severely bent wheel can cause a pull. I've seen this actually happen. In this case the pull always seems to be toward the bent wheel, at least in those few I've come across.
 
It's the tires. I had this same problem about 25 years ago. I finally had to leave the offending tires on the back.
 
I have run into this a few times and it has always been a tire - or I should say, replacing the tires always solved the problem.
 
Ahh! I missed that you just bought tires. For SURE take them back. Radial pull can't be cured and you need to have the tires replaced. Don't let them feed you the alignment bull. Pull doesn't change when tires are rotated when alignment is off.
 
Originally Posted By: yonyon
A severely bent wheel can cause a pull. I've seen this actually happen. In this case the pull always seems to be toward the bent wheel, at least in those few I've come across.


I'm trying to picture what kind of defect in a wheel could cause a consistant pull without causing a noticeable wobble at the same time, either in the steering feel or in a wiggle of the rear end, depending upon where the tire is. When a belt slips off center, it effectively causes a change in camber at that wheel, and I can see that happening in a way which causes a pull without necessarilly causing a wobble - if the misplacement is more or less uniform around the tread. The reason I am interested in this is because bad tires, even brand names, have caused me a bit of grief over the years.
 
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