My spedometer, odometer and trip odometer quit while I was driving the other day. I was going about 40mph and it just stopped working. How easy is this to fix? Is it the cable from under the dash to the tranny or is it something in the spedometer mechanism itself. My car is a 1981 240d with approximately 176,000 miles on it.

Most likely the speedometer cable itself has broken. You must pull out the dash panel and disconnect the speedometer cable...then pull out the flexable cable itself from the housing. Fastlane probably sells a replacement.

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'84 300D ~90k
'82 300SD ~171k
'82 240D ~175k
'96 Ram 2500 with 12V Cummins & 5 speed ~130k

http://dieselgiant.com/repairyourodometer.htm

Check this link

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1984 300SD Turbo Diesel 150,000 miles

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That's a nice pictorial, but I don't think it addresses all of the opening poster's issues. He reports that his speedometer has ceased to function.

So give him some useful information then.

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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No need to take offense, but I think the pictorial to which you linked specifically addresses issues where the speedometer proper works, but something is amiss in the hardware to drive the odometer and/or trip odometer. That's a fine procedure to know, and I've done a similar one msyelf. I don't see, though, how that can possibly solve his problem if the speedometer itself is not functioning. If I'm misunderstanding something about this, then please, let me know so that I'll be better informed!

I think Ken in NC has already suggested the first thing I'd suspect - the drive cable.

If everything up to the speedometer were OK, then I'd check the speedometer itself. I don't know anything about fixing the innards of the speedo proper; if it were broken, I'd probably be resetting the odometer on a spare unit and installing it as a replacement. After that, maybe some research here to see if there were anything to be done on a DIY basis to fix the sick one. If that came up dry, I might end up taking the sick one apart for my own edification and amusement.

These links may help you.

Sticky: Organized MB DIY links
Body Electrical:
Organized MB DIY links

Have a great day.

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