Tire shop claims replacing one tire may damage transfer case?

[faz]

Hi everyone,

Picked up a screw in my rear-left tire and it is not repairable. The tires have about a year more life in them (10k or so miles, I think.) I prefer not to change all tires, or more tires than necessary, at this time.

I have always used the local Americas Tire store, and have liked their service and prices and have been using them for the last 10 years. The service adviser there said that they *highly* recommend changing all tires as the in the 4x4, the transfer case could be stressed and damaged if only one tire is changed. I asked them to just leave the spare on and I will think about it.

I don't think changing one tire will cause any problems for transfer case, but then again, I thought I would ask the pros on this site. Have you had any experience with this before?

[AzNMpower32]

In the X3, it has led to cases of premature xDrive transfer case failures, or at the very least, unusual and unpredictable DSC behaviour resulting from the different rotational speeds. At the very least, replace a pair then wait a couple of months if budgets are tight but ultimately the system is sensitive so four is a safer bet.

[rph74]

If you have only 1 year left on your other 3 tires, you will indeed need to replace them. My local dealership said that they are comfortable with a 5/32's difference max on the tire gauge. And no, I was not buying the tires from them.

FWIW tire rack offers shaving services where if you were to only buy 1 tire, they can shave it down to match the other 3.

[RickM5X3]

For the T-case, the concern is the different revs per mile front vs. rear. But side to side differences can be also be tough on a differential. We had a T-case start to whine on our X3, and the dealer cited the Goodyear Eagle F1 setup that had too many revs per mile difference between the front and rear on the staggered setup. It was the correct sizing for the wheelset, but each brand of tires might have slightly more or less revs per mile ratios. OE tires tend to have less of a % difference, and that's likely not coincidence. Long way of saying that the tire store is making up a story, but hard to tell how material it is. Heck, you can probably adjust revs per mile readily by tire pressure settings.

[jst2878]

yes, dont do it. change all four if u can or at least fronts or rears together. use the same brand

[igosal]

Why don't you find yourself a used tire from Craigslist or an unbranded tire shop? This way it will have wear as well to match the wear on other tires. You'll save money too on one tire and then after an year, you change them all.... I would have gone this way, for sure.

[TowX]

The factory says a 1.5% variance in tire rotational length is acceptable, but nothing more. The difference between a new tire with 13/32 tread depth and a worn out one with about 4/32 is close to 2% variance. If the new tire is 13/32 and your old ones have more than 8/32 you're probably OK, but if the tires are worn more than that I wouldn't replace just one.

An option for you is to buy 4 new ones, then list the three used ones on Craigslist or Fleabay for sale to recoup part of your money.

[IanP]

Just a thought, the wheels never travel the same distance while the truck is moving as you will always be turning corners, and even if you are moving on a straight road then your course is always a slight weave. How do the diffs etc cope with that?

[faz]

Thanks for your feedback, guys. Really appreciate it.

The other wheels have 5/32 and 4/3 left on them, so they are almost there as far as replacement is concerned. If I lived in a bad weather condition (rainy or snowy) then these would definitely be changed right now, but given our very mild climate here in the bay area, and my short trips to work and back in busy streets, I thought I should try and get as much out of these tires as I possibly can.

with your feedback above, I will definitely NOT replace only one tire with a new one. (Tirerack shows the new Michelin to have 10/32 thread depth and that is too much variance.) It will be all 4 tires if I decide to go with the new ones, which right now I think that is the route I will go. I will take a look at local craigslist and shops to see if I can find a used 18" Michelin energy mxv4 to match the old ones. But if I don't find one in a couple of days, I will just go ahead with the 4 tire replacement, perhaps go to something cheaper like Yokohama YK520 that Americas Tire has (their own exclusive brand) that is almost 60% of the cost of the Michelin replacements. As much as I love the michelins, the $1300 OTD cost is a bit steep at this time for me.

Thanks again for all your helpful comments.

[JCL]

Originally Posted by IanP

Just a thought, the wheels never travel the same distance while the truck is moving as you will always be turning corners, and even if you are moving on a straight road then your course is always a slight weave. How do the diffs etc cope with that?

If you are asking how the electronics cope with a slight rotational speed difference, they have a programmed tolerance (limit) before a warning light comes on or other action is taken. As an example, around a corner is fine, one spinning wheel on ice is over the limit and traction control is engaged.

If you are asking how a mechanical differential manages to divert torque to two wheels that need to turn at different speeds (leaving aside limited slip diffs for a moment) then the X5 differential is exactly the same as the one in a Model T. Watch this video, it is pretty good: