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Tire Replacement

I recently had my 2 front tires replaced on my Jeep Grand Cherokee 4x4. I told them that I had been told all 4 should be replaced at once on a 4x4 & they said no, the 2 back were fine. Now my husband says I am tearing up the transmission if I drive it…therefore it has been sitting in our garage awaiting either 2 more new tires or confirmation that the tire tech really did know more than us. Who is right? Will it really tear up the transmission to have only 2 new tires in the front?

Check the owner’s manual. There are some four wheel drive cars that would need all four change and some that would be happy with just two changed.

BTW, the best tyres belong on the BACK, not the front.

I am very surprised the tire shop didn’t know about this - and even more surprised that they didn’t take the opportunity to sell 2 more tires. Plus new tires should go on the rear. They may be honest, but they aren’t knowledgeable.

Yes, you COULD damage the drivetrain (it isn’t a 100% sure thing!), but given the cost of 2 tires vs the cost of fixing a drivetrain, the cost / benefit ratio is all wrong.

The general rule is all AWD and 4X4’s need to have all 4 tires replaced at the same time with 4 identical tires. Then regular rotation to be sure they don’t wear at different rates.

The owner’s manual will tell you if all tires have to match or not.

If not, the tires with better tread belong in the back for safety reasons. You can usually recover from the front end losing traction, but not the back end. I’m surprised your tire shop didn’t enforce this. Most of them do these days.

Not enough information to answer your question. There are different 4wd systems available for the Grand Cherokee based on model year, engine and options. The SelecTrac 4wd system, for example, does not “care” about tire size mismatch since it is either fully locked (in 4wd part-time) or an open differential when in 4wd full-time.

New or old, makes little difference. What is important on any AWD or 4WD vehicle is that all four tires have the same circumference…So when they roll, all four axle shafts rotate at the same speed. The circumference can easily be measured with a simple tape measure…

If the diameters are exactly (within 1/4") the same, that’s close enough. When you are in 2WD, there is no problem regardless as the axles are not locked together. 4WD should never be used on dry pavement in any case…

New tires on the rear may not at all be critical if the old rear tires had good tread.

Tear up is an overstatement. Slowly wear out may be better if it is true. Yes, check the owner’s manual.