Tire change question on AWD

[B.Spilner]

So we had a non repairable tire on our 2008 ford escape AWD. We spoke with a few people and they said to change all 4, but if thAts to expensive change 2.

So we only changed the back tires. The front still have about 60-70%.

I measured with a tape measure and the new rear tires are an inch higher then the fronts... How bad is this gonna be on a AWD vehicle?

[Sugarphreak]

...

[lilmira]

That sucks. Happened to me once, one season old RE11. :banghead:
Ended up replacing two.

You need a pair for sure so grab those first and see if you feel anything weird with the handling.

The more accurate way would be to measure the difference in tread depth, not sure about overall tire height, the front tire may be lower with the weight of the engine. From that you can figure out the difference in circumference.

[RickDaTuner]

1" of height difference is significant, the official Ford spec for differing tire tread is 30% of the tread depth so if your tires are at 8-9/32nds and new they come 10-12 you will be at about the limit.

The ford escape uses what called a Power Take Off Unit that is mated to the Transmision, as has been mentioned it is FWD based due to the front axle being driven directly from the transmission. This does help with varying tire circumferences, but the PTU unit is very suceptable to over heating, and will develop a vibration over time.

If you want to be 100% sure change the other two tires in the near future, but there is no immediate danger to your drive train as there are no significant limited slip differentials to worry about.

If it was an Edge, or Explorer, then I'd be replacing all at once.

The tolerance limits are also published in your owners manual.

[ExtraSlow]

If it was me, I'd put the two newer tires on the front. They'll wear qucker and you want the best rubberon your steering/stopping end.