This little problem has been bugging me for some time, now I want to see if there is a DIY fix or not. The odometer/trip meter on my 280 SEL tends to stick, or stop turning, once the interior warms up. If it stays cool everything works fine, if I park outside on a warm day, it stops working. The speedo functions normally at all times, only the odometer stops.

I noticed this shortly after I calculated my mileage at under 5 MPG after a fill up last year. Now I watch the odometer closely, and keep a note of missing miles for fuel mileage purposes. Of coures the missing miles help lower the insurance, as it showed less than 7,000 miles last year, but I'll never earn a mileage badge at this rate either.

Is there a home remedy for this repair, or am I better served by sending the speedo head off to a speedo shop? Palo Alto Speedo, here in California, will do a complete rebuild of the VDO unit for about $125.00, but if I would prefer to fix it myself.

Also, I have done some exploratory work on the instrument cluster. The knurled nut which should hold the cluster in is missing, so I can slide it out without difficulty. It will come out just far enough that I can see the speedo cable connector, and the wiring harness. I can almost get to the oil line fitting, looks like a 10mm. The line to the temp gauge makes it appear that the temp gauge is mechanical rather than electric, with no obvious way to disconnect for removal.

Are there any hidden tricks to getting the cluster out far enough to gain easier access to the connections and fittings? Where should I disconnect the temp gauge line? Would it allow the cluster to come out further if I disconnected the speedo cable at the transmission?

Thanks for all the help from this group. And all you diesel head, keep asking your questions...I am learning a lot, getting ready for when I change over to an oil burner(hopefully by the end of the year).

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Mike Tangas
73 280 SEL