The Odometer on my 94 850T quick working sometime ago, although the electronic mileage still worked. I found the gear in the odometer was missing a tooth. This is a common problem. I found the part at www.ipdusa.com (a Volvo & Suburu specialist) for $50. The best part was the instructional DVD, it's was a Very helpful, Step by step guide on removing the Instrument cluster & replacing this TINY $50 part.