I own a couple rwd volvos but my question is this..... AWD Ford 500 ... drivetrain is CVT volvo. My tire guy says if one tire gets worn uneven with respect to the others I will need to replace all 4. I do rotate the tires every 8-10k on general principle. He says the front to rear viscous coupling will suffer if tire size is off even a little. I think he is wrong ... what say the panel of experts?

Before the Haldex AWD arrived for Volvo, your tire guy was correct. But, it is the bevel gear that goes bad.
The Ford 500, also known as Taurus, has the newer style AWD and is not as problematic as the 1997-2001 cars. A little tire wear will not kill it.

Of course, rotating tires and never replacing just 2 makes good sense. I rotate my tires on my 1998 awd every time I change the oil.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

Thanks Klaus. Good info for all of us..