Speedometer is working but not Odometer. Any suggestions on fixing this problem?

Is there electricity involved in counting mileage or is it mechanical only?

I simply checked fuses but nothing else yet...

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1985 300SD

The parts are plastic and have dried up and probably broken. It is 28 years old. You have to pull the speedometer out and basically rebuild it.

I disconnected all of the parts to the odometer and the speedo worked the best I have ever seen it. most of the parts were almost like dry clay and ready to fall apart at the slightest touch.

Probably not the answer you wanted.

Before you take out the instrument panel, disconnect the battery. I didn't and I think that fed back to my GP relay transistors which melted and ruined my relay.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

Not sure about the 126 SD's but the 123d's odometers are mechanical and are well known for a gear slipping on the shaft. Fix is pretty simply and is documented on here many times. Search should give you the procedure for repairing it if the odometer is the same as the D's.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Common problem. Try these guys: Odometer Gears - Mercedes-Benz - 126 Chassis 79-91 Diesel

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Sam

84 300SD 350K+ miles ( Blue Belle )

There was a recent post on a cheap way to get the gears. Search for the post. Also see speedometer gears for tooth count. Enough info is now available to do the repair for next to nothing.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

The odometer fix in my W123 was easy but took some time and patience.

Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

Ok, will look into it more. Thanks for the direction.

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1985 300SD

It might just be a loose gear, atleast that was the case in my 124. In that case, take out your odometer, look if one of the two gears is spinning freely, and just glue that onto the shaft. But be careful not to glue the whole assembly together, nearly happended to me!

Good luck with your repair

.

the shaft gear is most common issue and the third (usually yellow-ish)
gear on the left side of the shaft.
if the teeth are not in their proper height even after rebuilt you will have
erratic readings...

I have rebuilt my 2 clusters recently (120 and 80 mph) it is easy
if you have proper spare gears.

try to take out instrument cluster by dismantling the left speaker
and pushing behind,..it is much easier than with hard L wires.


cheers

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

it's a 126. the speedo/odo is electronic, and has plastic gears that disintegrate. it's not anything similar to the 123/124.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Ditto.

And if you will note the link provided, there is a link (in blue) with instructions to prevent problems on both the removal of the old gears/bushings and installation of the new ones. I would rather spend an extra $10 for gears from someone that provides this service and expertise.

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Sam

84 300SD 350K+ miles ( Blue Belle )