The correct answer is to replace the pair of tires on the same axle so they are matched. There are a few vehicles out there that have full-time four-wheel-drive, (not the same thing as four-wheel-drive or all-wheel-drive). Some Jeeps and some GM Astro Vans are examples. On those the transfer cases can easily be torn up if all four tires don't have exactly the same circumference. That means not only buying four new tires of the same brand and model, they must be from the same batch.
The incorrect answer is I recently had a broken belt on my '88 Grand Caravan. Since I get the last ounce of life out of everything, I could almost see the air inside them! I felt the slightest wobble almost six months ago, and being a suspension and alignment specialist, I knew what was happening. Also, it seems to be real common for some tires, Goodyears especially, to develop broken belts about the time the tread is worn out and the tires need to be replaced anyway. The last 30 miles on that tire would have shaken out your dentures, and there's no way I would put a passenger in there with me. I was taking a huge risk instead of mounting up a different tire in the freezing snow. I was expecting a sudden blowout but when it finally let go it took about a mile to go completely flat. There was plenty of warning from the rumbling and mushy handling.
That doesn't mean you're going to get the same warning. A blowout is always a possibility. The first thing I'd do is look at all four tires to see what the tread wear and wear patterns look like. If any tire is worn more on one edge or if two have a choppy pattern, start with an alignment. The vehicle can be aligned with the old tires. The preferred procedure is to have new tires installed and the alignment done at the same time by the same person so he can "read" the wear patterns. The next best is to have it aligned with the old tires, then buy new tires somewhere else, but tell them any problems they see have just been corrected. The least preferred is to buy new tires, then have it aligned somewhere else later. You'll still get a good alignment but they won't have the advantage of reading the tire wear. Think of going to a chiropractor with a brand new pair of shoes so he can't examine them for clues.
If the other three tires are in good condition, put the two rear ones in the front, then consider putting the full-size spare on the rear with the old front one. The tire with the broken belt can be the spare. You can thank the politicians for the steep rise in new tire prices. They always forget about the "Law of unintended consequences". Because of their stupidity resulting in higher prices, people are using up their tires more and running them to dangerous levels. Hydroplaning and blowouts will occur more often resulting in more crashes than what they thought they could prevent. Mechanics are also starting to change their attitudes a little. Instead of pushing you to buy four tires, they'll go for just two instead. Four tires was how they looked out for your best interests in the long run. Two tires is how they look out for your wallet today.
If two or all four of your tires are close to the end of their life, new ones will be an inexpensive worthwhile investment. Your vehicle is new enough that suspension springs and bushings aren't worn excessively and you'll still have that like-new ride and handling. Might as well enjoy it.
I should mention too for the benefit of others researching through this forum that wearing tires down to the steel belts, as I did, is really stupid. In some states you can be fined if they find tires like that on your car. Lawyers and insurance investigators love to find things like worn tires and altered ride height. They will convince a jury that you were partly at fault for a crash caused by the other guy running a red light because you were less able to avoid the crash, ... And they will be right. I took a big risk and I'm not suggesting anyone else do the same thing.
Tuesday, February 19th, 2013 AT 5:25 PM