Tire Size and Transfer Case

I have gotten conflicting information on this. Please help. I have 15x8 inch rims on my 4x4 2000 GMC Jimmy. I have 235/70/15 up front and 275/60/15 in the back, both of which have a 28" diameter. I ordered them from the tirerack.com, the person who helped says that this is fine because the difference is minimal. I was told by another agent at the tirerack that this will destroy my transfer case. Any ideas? Thanks!

Likely yes. When you engage four wheel drive and disengage it is it banging coming out or not coming out right away? I had a difference of 7mm from one tire because of a blowout replacement and it caused havoc with the four wheel drive. Purchased three new tires so all the tread depths were the same and the slamming disappeared.

I have not engaged my 4wd...too scared! Transfer Cases are big money

Like the post above I have seen just excessive wear of one tire cause problems with the 4WD and with ABS.

I personally would not even think of risking it. - Ever seen how much $$$ rebuilding a transfer case can cost if you need most of the internals replaced?

Hope this helps.

Thanks for the heads up!

The difference is 0.1 inch on the circumference and I do not believe it will be a huge problem whatsoever.

I think you are safe.

Try this to determine if all of your tires are turning with the same diameter. Make a chalk mark on the top sidewall of each tire. Drive the truck in a straight line (use a parking lot) for 100 yards or so and then check to see if the chalk marks are still all in the same positions. If they are not, you will have a problem.

I went here and they were practically identical.

http://miata.net/garage/tirecalc.html