Different size tires on all-wheel drive

OK, here is my issue: I had 4 new tires put on my car this past winter. I paid for 735 R15 tires. The dealer whom I won’t name at this time installed one correct tire and 3 715 R15 tires. The odd size tire was mounted on the front passenger side. I have been driving with it like this for approximately 6 months. My car broke down last week - a problem with the front drive train. From the day the new tires were put on the noise was excessive. I complained and was told it was b/c I bought a mud and snow tire with heavy tread and the noise was tread noise. I am now in a fight with the dealer’s insurance company on responsibility. My hubs are shot, and the transfer case is leaking. There is not telling how much damage is done to other mechanical components as a result. Any gear heads out there have any advice on this???

None that you haven’t learned the hard way…to keep the same size tires all around.

Honestly, I think if you got all the documentation together and took this to small claims court against the dealer you’de have a very strong case. You deserve and entire new front end and new tires of the correct size.

You should win this one. What does the invoice the dealer gave you say? Does it show one tire a different size from the other 3?

If yes, the dealer will claim you were informed of the different sized tires and ok’d it. If not, then the dealer installed tires that were different from what you were billed and didn’t disclose the different tire sizes.

The different sized tires are not good for the vehicle and damage can result. If you suffered a broken transfer case and/or differential on the axle with the wrong size tire that is consistant with the kind of damage expected when running different sized tires.

Thanks for the reply. The insurance company is not bulking yet, and they have been helpful to-date, but until they say for sure they are accepting responsibility, I have concerns I am going to get stuck with a large bill as a result of someone elses negligence. Even if I go to court later and win, I am out the money now which in this current economy hurts. I think I have a good case too, but you know how that goes… Thanks again!

Only a ‘forensic’ tear down of the AWD system will be required to know if there is more damage. If the dealer’s insurance is giving you grief, see if your auto insurance company and maybe your home owner’s insurance can help. The next step is talk to a lawyer.

The invoice reflects four (4) 735 R15 tires. I have been told the 715 R15 tires are two sizes too small and are not even properly rated for my vehicle. I have been driving my family around in an un-safe vehicle! That is scary. I wonder where the checks and balances are with these tire companies. When you pay for a service, it is assumed you are paying for professional services…

6 months with mismatched tires on AWD pretty much means there’s damage, and it’s their fault for installing the wrong tires on there.

You have a very strong case, but here’s how to bolster it further:

  1. Get the tire sizing correct. The form is XXX/YYR15, where:

XXX is the width of the tire in mm and it will be between 155 and 315 - likely 235 and 215. Notice the last digit is always 5.

YY is the aspect ratio and it will be between 35 and 85, likely 75. It will either end in 0 (Zero) or 5.

  1. Take photos of the tires and in particular, the tire size.

  2. Take photos of the damage. You will need someone to either testify for you or write an affidavit that the damage was caused by the mix of tire sizes.

Perhaps the threat of a lawsuit would be enough to shake the insurance company into action. If not, file the lawsuit, get the car repaired, and save the bills to be presented in court.

What kind of vehicle are we talking about here?? It took you 6 months to spot this?? You spend $400 on a set of tires and you don’t even look at them??

As a part of the body of evidence, I suggest you photograph the sizes on the sidewalls of all your tires and copy the recommended tire size page from your owners’ manual. Bring the actual manual with you to court should you go.

Were this to take this to small claims court I think you’d win hands-down.

Believe it or not, most people do not buy tires and then go read everything on the sidewall of all 4 tires to verify that they’re correct. Don’t attribute the habits of gearheads to the rest of the population.

I agree. Even I do not do that, although I do a “walk around” to spot any obvious anomolies, and I always reset the pressures using my own bourdon tube gage…but even then I don’t read the sidewalls unless something seems “off”.

It took 6 months off the diffs running at different speeds to burn them up and lead to identification of the issue. Who looks closely at the sizes of tires?