I had a similar problem with the gauges on my 300sd. Started of the fuel gauge didn't meaures the fuel in the tank properly. Learned a whole lot from dissassembling and reassembling various clusters. Now, five clusters later, I have a fully functional unit. I have 2 or 3 300sd gauge clusters laying around at the house, but can't remeber which one's have good gauges, and which ones have bad gauges. If it comes down to it you should be able to buy a whole entire cluster for less than 100 dollars. Check ebay, user id usedpartshunter, that is who I got mine from. If you have access to a gasoline speedometer though, you might be able to make it work to an acceptable degree. Of course the diesel units don't have the economy gauge, but other than that, the oil, temp, fuel gauges are virtually the same. You would though have to get a wiring diargram of the cluster and rearrange the pins to match the gasoline's board arrangement. Probably eaisier just to get another one though.