[ChevLoRay]

I put a new set of tires on my Tundra. It seemed to shimmy a tiny bit, so I had it aligned. Better, or not? I couldn't tell. So, I went back to the WalMart where I bought them. They checked the balance on all of them, said that the balance was off just a little, and I took off, again. Still, something didn't seem right. So, I went back. They re-checked the balance, again, saying that they had some balance issues. Then, they rotated them. At that time, the tires didn't have 1K miles on them. Now, the previous sensation of shimmy, became a slight bounce in the rear end. Back to WallyWorld. They checked them and determined that one of them was out of round. So, for less than $5, I had a new tire.

My thinking is this: If a tire is out of round, out of balance, or whatever is causing the shimmy/bounce, it will ultimately affect another tire. Once the new tire was on the truck, and I had driven it for about 1000 miles, I either got used to the ride, or it was better.

This was on a set of Continentals, following a set of Michelins. From one brand to another, you will feel a difference in tires, even if they are the same size. I had also put a set of Continentals (LT235-15's) on a '96 SilverDollar, and they were so much better than the Firestone Firehawks that had been on it. With an 80K mile warranty, I'm satisfied, for now.

So, that brings us back to your problem. You can see that it took 3 trips to find the out of round tire. It isn't common for these Continentals to be out of round, so they didn't think of it as soon as I did. I had previously replaced my steering rack mount bushings with urethane items, so that wasn't an issue.

But, do you know if the tire store checked for out of round? If not, it's worth checking. Usually, drive line vibrations won't "just show up" when you get new tires. How many miles on these new tires? Has anyone checked the run-out on the wheels? It should be obvious to the installer, when they spin 'em to balance them. Have you, or another driver, flat-spotted them in a panic stop? I am sure the answer will be a simple one, once someone figures out what it is.