Odometer stops in hot weather

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sbb
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Hi the odometer and trip meter in my 1989 W460 stops working during the summer months when the temperature gets up. Has anyone else encountered this problem? Any quick fixes or does something need replacing. Thanks.

 

Arnie
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Re: Odometer stops in hot weather

Thermal-expansion and softening of grease in higher temperatures may be the cause of intermttent operation. But, I think you will find that the internal worm gears are essentially worn out. Problem is that it's  impossible  to open the speedometer without uncrimping the front bezel, which risks breaking the glass and some effort to replace and repaint, if it it gets too mangled in the process. Use a screwdriver from the rear of the bezel to open-up the crimp and work round slowly.

I think most of these speedometers develop this problem approaching 100,000 miles.

Jdring
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Re: Odometer stops in hot weather

I had this in my 1987 230GE.  The speedo worked, but the Odometer mostly did not.  It kept my mileage low for the insurance! (joking)

I always assumed it was the end of the drive cable into the speedo unit... turned the speedo indicator arm on the clock spring, but not the gearing for the odometer.  Since the drive cable is metal, I assume the female locator it pushes into is plastic, and has worn.  Maybe someone has an exploded view of the components here.

My guess would be to replace the whole speedo with a replacement?  Since the one you have is wrong anyway.

Edit: there's loads of similar stories on here - just search 'speedo'.   Some say likely the cable, but then the cable didn't fix it, so I stick with the speedo end of things.

sbb
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Re: Odometer stops in hot weather

Thanks. So it looks like a new Speedo.

Can anyone let me know the best place to buy one? I don't mind if they are new or second hand, as long as they work.

I'm after a few parts including:

- Front passenger side window motor

- Speedo

- Fuel Sender Unit

- Interior Blower Motor

Arnie
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Re: Odometer stops in hot weather

The cable does wear, particulary if not well lubricated internally, and this can cause a jumpy speedo pointer. You can open-up your existing speedo. Nothing to loose. And see whether the odometer  gears can be re-adjusted.

(I opened up mine some years ago and managed to get it going again, but it only lasted another 10k miles or so.)

 I think I've seen a replacement version that now has an LCD display for the odometer.