Tire Size and Transfer Case

[JimmyGold]

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!

[swalt]

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.

[JimmyGold]

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

[GMCTech]

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.

[JimmyGold]

Thanks for the heads up!

[BlazerLT]

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.

[swalt]

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.

[BlazerLT]

I went here and they were practically identical.

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