What is the replacement interval for the serpentine belt on a 1998 Volvo V70 XC? on 1998 Volvo V70 XC

It was last replaced three years ago (7/09); since the car has been driven about 29,200 miles.

Asked by for the 1998 Volvo V70 XC
its due anytime
Many thanks. I thought that because I have only driven the car less than 30k miles, I could wait. I guess you advise otherwise?
preveniyive maint is always a dood idea like oil changes
2 more answers , 2 more comments
Have a look at the belt, the side that touches the pulleys has a ribbed surface. If it shows any cracks in the ribs, replace the belt.
Many thanks. Will do as you said.
Timing belts on this vehicle are due every 70,000 miles. So you have about another 40,000 miles to go until its due again.
I probably misled you. It's the Serpentine belt, I.e., the belt that transmits power from the crankcase to the AC compressor, water pump, and alternator, that I meant. What is the replacement interval for this "auxiliary" belt on my 1998 Volvo V70 XC? Many thanks.