Assuming that yours is the same as my W123, The problem is that the shaft
that holds the number wheels is pressed into a pot metal gear. It is
slipping at this press fit. I fixed it by taking it apart and drilled and
tapped the gear for a 0-56 set screw.
There is a website that describes a repair using Loctite. This makes me
nervous because the assembly can be destroyed if the Loctite gets in the
wrong spot.
If you are not up to this, I might be interested in repairing yours. You'll
will have to ship me the speedometer housing.
On Jul 30, 2:12 pm, Chip <chip.w...@ieee.org> wrote:
> Tom Mills wrote:
> > The speedometer on my 1983 380SL is accurate, but the odometer has started
> > slowing down. It now turnover one mile for two driven. I started
noticing
> > this when it appeared the gas mileage was dropping off.
>
> Don't have an answer, but it's great for re-sale value!
>
> Chip
There are shops that you can find online that repair/rebuild them for
you. I don't have a name, but I have seen them and you can find via
google.
Wan-ning Tan - 06 Aug 2008 14:05 GMT
Exactly what I did last weekend. The metal drive gear next to the
lowest odometer digit (i.e. the single digit) loses its grip to the
shaft, so mileage is no longer registered correctly. When the outside
temp is cold (below 10C), it may function (though mileage still off).
When the temp is higher, it does not register at all.
Take out the cluster, then the odometer. The cable drives the
speedometer and the worm gears next to the highest digit. See if the
shaft that goes through the odometer digits moves in/out. There should
be very little play because the shaft is held in place by the metal
drive gear.
If the shaft is loose, slide it out completely. Note how the odometer
digits go with the small advance gears on top of them. When the shaft
is out, all digits will FALL OUT. You need to put the digits back to
engage with the advance gears correctly, or otherwise the odometer may
stuck. The single and tens digits are different than the others. This
prevents the odometer goes backward.
I have a spare speedometer cable. I use it (and a drill) to check the
operation of the odometer before putting it into the cluster.
Last note. The speedometer hand and face were taken out to disassemble
the gear. I did not caliber the hand (did not know) so the speed now
shows like 10 mph faster than actual.
> Assuming that yours is the same as my W123, The problem is that the shaft
> that holds the number wheels is pressed into a pot metal gear. It is
[quoted text clipped - 29 lines]
> you. I don't have a name, but I have seen them and you can find via
> google.
Tom Mills - 08 Aug 2008 03:45 GMT
Mine turned out to be an electronic VDO odometer, and the small gear had 50%
of the teeth missing. I have ordered a replacement gear set. Turns out
this will be a easy fix with the correct parts.
Thanks for all the advise. I would not have taken it apart without the good
advise here on the news net.
Tom Mills
-------------------------------------------------------------------------
> Exactly what I did last weekend. The metal drive gear next to the lowest
> odometer digit (i.e. the single digit) loses its grip to the shaft, so
[quoted text clipped - 55 lines]
>> you. I don't have a name, but I have seen them and you can find via
>> google.
Jens - 09 Aug 2008 10:54 GMT
> Mine turned out to be an electronic VDO odometer, and the small gear had 50%
> of the teeth missing. I have ordered a replacement gear set. Turns out
[quoted text clipped - 68 lines]
>
> - Show quoted text -
Mine just stopped working (W140) when changing from 199.999 to
200.000. Probably same problem.
But where do you get replacement parts? (Mercedes only has comlete
instrument cluster as replacement part).
Jens - 09 Aug 2008 22:23 GMT
> > Mine turned out to be an electronic VDO odometer, and the small gear had 50%
> > of the teeth missing. I have ordered a replacement gear set. Turns out
[quoted text clipped - 79 lines]
>
> - Vis tekst i anførselstegn -
Fixed the problem. It was the highest digit sticking, som stepper
motor had too little power to turn it. Once passed to 200.000 it
worked fine again. Same time I fixed a speedometer offset problem.
Tom Mills - 10 Aug 2008 20:35 GMT
> But where do you get replacement parts? (Mercedes only has comlete
> instrument cluster as replacement part).- Skjul tekst i anførselstegn -
>
> - Vis tekst i anførselstegn -
I found the gear set at the following web site.
http://www.odometergears.com/mercedes.html
Tom Mills
Tom Mills - 11 Aug 2008 21:09 GMT
The replacement gears for my odometer came in today and it is now, FIXED
Thanks again for all the help!
Tom Mills
-------------------------------------------------------------------------
>> But where do you get replacement parts? (Mercedes only has comlete
>> instrument cluster as replacement part).- Skjul tekst i anførselstegn -
[quoted text clipped - 5 lines]
>
> Tom Mills