AWD question

[jlmilligan]

This is a non Toyota question but maybe someone can shed some light on this question for me. Is it bad for the AWD drivetrain to replace one bad tire when all the rest have 35% to 40% wear? Or should you replace all the tires? This is on my buddys A6 Audi. He really doesn't to spend another 6 bills just before christmas. Audi says he has to replace all of them or it can damage the drivetrain.

 

[CJ3Flyr]

This is a non Toyota question but maybe someone can shed some light on this question for me. Is it bad for the AWD drivetrain to replace one bad tire when all the rest have 35% to 40% wear? Or should you replace all the tires? This is on my buddys A6 Audi. He really doesn't to spend another 6 bills just before christmas. Audi says he has to replace all of them or it can damage the drivetrain.

That's a tough call. If it's the same brand/model of tire from the same plant he'll be fine. Over time even fairly small differences can cause issues. The difference between 35-40% tread and new tread isn't enough to cause an issue generally.

Many times the "hard line" that dealers take about replacement is partially about liability. The manufacturer can't control what goes on at the tire company. The tire company won't guarantee the new tire is exactly the same dimensions (excluding simple treadwear) as the old tires and therefore say 'replace all'.

On the Trooper message board I used to go to some guy had a heck of a time with faults, screwy ABS etc. It turns out 3 of his Michelins were Thai and the 4th was US or French. There was 3/4" + of a difference in height. It was the same model/size...


:cheers:

 

[Thai]

This is a non Toyota question but maybe someone can shed some light on this question for me. Is it bad for the AWD drivetrain to replace one bad tire when all the rest have 35% to 40% wear? Or should you replace all the tires? This is on my buddys A6 Audi. He really doesn't to spend another 6 bills just before christmas. Audi says he has to replace all of them or it can damage the drivetrain.

I would think that he needs to replace at least the other tire on the same axle as the bad tire. I am not too sure that i buy Audi's requirement. For example, you have two new tires up front and two older ones in the rear. The center differential should be able to handle the very slight speed differences between the front and rear axles. Think about how many tires your friend has to turn left or right on the streets...the center diff handled those speed differences well...so, why not now?

But, yeah, ideally, if you want everything perfect, then get 4 new tires.