I have a 07 dodge ram 1500 4x4. Have a tire that cant be fixed, went to buy just one tire to put in place of the bad one and they wont sell or mount the tire saying that I have to have 4 new ones or I will mess up the drive train. Is it ok to go and buy one tire the same size as the other 3 and put on truck even if the tread depth isnt the same? Will I do any damage to vechile? I dont know current tread depth on 3 tires they prob have 30,000 miles on them I dont know, I tried to save money and bought them used. I will never do that again, now i just want to make them last before buying 4 new ones.
The rest of the puzzle remains unknown.
Is it a 4x4 ?
What is the tread depth of the other 3 tires ?
What is the age of the other 3 ?
Some tire shops can shave down a tire to match the circumference of the others
but
You’d be wasting good money on a new tire to shave it down half way only then to be buying all 4 within a year.
OP said it was a 4x4 which presumably leads to the difficulty of differing tire circumference. Another (although slightly risky) strategy is to buy a used tire from a shop that has a close circumference match. But I agree, if you’re near needing tires anyway, just bite the bullet and buy 4. That’s one of the costs of running 4x4.
I don’t know the specifics of the '07 Dodge, but the vehicle’s sensitivity to different size tires depends a lot on the specific 4x4 configuration (AWD, differential configuration, etc.) Some older vehicles couldn’t care less because you disengaged 4wd unless you were off road and then slight differences in tire size are less important because none of the tires have solid traction. But you can probably find out how touchy your vehicle is to different size tires by searching for a Dodge Ram 4wd forum online.
I know nothing about the operation of a 4 wheel drive vehicle, but could the original poster use two of his old tires on one axle and buy two new ones for the other axle without causing damage. Two tires would be cheaper than four.
Once again, depending on the difference between front tire sizes and rear tire sizes, it could put added stress on the 3rd diff.
If you have a separate lever, or push button that you use to select 4wd when you need it and deselect it when you don’t, then you can buy just one tire, unless you have a limited slip differential on the rear, then you will have to buy two tires. The new tire(s) always go on the rear.
If your 4x4 is a “full time 4 wheel drive” or “all wheel drive”, then you do have to buy 4 new tires, or a used tire with the same tread depth.
You can buy a tread depth gauge for less that $3. With a 4x4, you should have one of these. You can use it to determine the optimum time to rotate your tires instead of using some arbitrary number of miles.
bought the 4 current ones used and they might have 30k miles on them right now? I’d say spring for the 4 new ones for piece of mind. They are telling you this because, as others have posted, you risk damage to your differential. It’s not upselling, it’s deferring liability; if you only buy 1 and it damages your differential, then they run the risk of you coming back and saying it was their fault, so they say buy 4 new ones.
Checking the tread depth won’t tell you much unless the tires are the same make model and size. What you need to compare is the diameter of the tires.
I’m with bscar here: Bought used and have 30K more? Probably close to wear out, so a new tire is going to be quite different in diameter - which means there is a risk of drivetrain damage. Very expensive!
Buy new ones!