The gear that wears out in the odometer suffers from plastic tooth fatigue regardless of whether you hit the trip odometer reset button while moving the vehicle or not. This is why the latest model vehicles have digital odometers and trip odometers. Less mechanical problems are encountered with digital odometers. This however does not solve your problem.

As the other responder noted odometergears.com and volvospeed offer help with supplying the plastic gear and directions to remove the instrument cluster. Nevertheless, directions to disassemble the instrument cluster to get at the odometer are lacking (unless odometergears now provides instructions on how to disassemble the cluster- I haven't checked lately). When I did this operation ( 1 year ago), I used a site called Tim's Tent (for cluster disassemly instructions). I cannot locate this site lately. I have noticed that ipd has just advertised that it will sell the gear and a dvd which instructs you in the methods used to remove and disassemble the instrument cluster for about $50.

You do no want to go to the dealer for this repair. They do not like to open up the instrument cluster as there are too many delicate electronic parts to break. They will want to replace the instrument cluster $800 and charge you two hours to labor to remove and replace the cluster.

Dan

Dan