I punched the odometer reset button and it went back to zero for trip miles. Then I noticed that the odometer is not registering mileage any more. The speedometer works fine; the mileage just does not change. So I am stuck on 259,000+ total miles and 0 trip miles.

Guessing that some gear has broken but I have not taken it out of the dash yet. Does anyone have a recommendation about what gear I should order - or what?

Thanks.

I bet you car was moving when you pressed reset?

W123 Odometer Repair Notes

HOW TO REPAIR ODOMETER IN W123 - Mercedes-Benz Forum

How to Repair Your Broken Odometer

Good luck

I bought a special replacement gear for the VDO odometer, use the above links if you haven't already, great resources

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Never be ashamed to ask for help.

1985 300D
1987 300SDL
1970 Jaguar E-Type OTS
2002 Dodge Intrepid (Traded In)
2011 Ford Crown Victoria

Does sound like you've got a broken gear. I recommend taking out your cluster and visually inspecting the gears. Order replacements from OdometerGears.com

I did my 82 300SD here:
W126 Odometer / Speedometer / Clock Repair - Imgur

I've heard this advice for the mechanically driven speedometer cars but I think the electronic ones are OK to push the button on. I've never had an issue. More than likely OP has broken gear.

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Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

I fixed both of mine using odometergears.com. Very helpful guys. Gear teeth number is important. Old eyes make it hard to count teeth. Used felt-tip pen marking first gear counted. Lots of light. Got it right the second time. They aren't exaggerating in respect to blowing things out with air. Get the set of 3 gears. You will need at least 2.

Great advice. No, the car was not moving when I reset the odometer and it stopped working.

Thanks for the help.

Anyone remember the post that tells how to bend a coathanger to remove the entire instrument section? Saw it years ago. Never had the guts to remove the entire instrument section but believe it just pushes in and is held by friction and perhaps a rubber gasket.

I remove the two bottom panels under the dash, reach up and push the instrument cluster out. Plus by doing it that way you do not risk scratching your dash or the cluster.

Well, have not heard of that method but it makes sense. Thought the indies just pulled it out with a bent wire like a coathanger, maybe somewhat stronger.

Thanks for the info.

Is there a single mechanism that runs the odometer and the trip meter or are there two separate gizmos?

Same gizmo runs odometer and trip meter. I never got around to replacing the gears on my 83 300sd before I crashed it. Now my 86 300sdl needs the gear set. A soon as I get my radiator issue dealt with I am going to order the gears.

Guys, thanks for the advice.

JamesDean - looked at the pics you sent. Is there any text here or only pictures? If no text, do the plastic gears just prize off the spindle or how do you get them off? Maybe they are reverse threaded? Assume when I pull the cluster out of the dash I will recognize the parts or do I have to take off a cover to see the gears?

Thx

I will confirm the easiest method (for me anyway) to remove the cluster is to push from underneath. If its never been done, you'll have to thread your way around the sound deadening mat, but its easy enough. Using the hangers method scratches your dash and cluster assembly, although going that route might be easier if you lack the flexibility to snake your hand into the dash while kind of halfway laying on the ground/roll pan.

In my odo case, I did not have a broken gear, but rather one of the pressed-on pot metal gears came loose on its axle. It was pressed on and simply held up by friction, and eventually wore enough internally to allow it to spin freely thereby killing the odo. I recall this failure mentioned in one of the diy threads. A little dab of stupid glue on both sides to "lock" it back on the shaft, let dry, reassemble.

It is a single gearset that turn both the trip and main odo. If the potmetal bit is freewheeling, it will kill both. If the main odo works but the trip doesnt, its a stripped plastic gear between the two.

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1985 MBZ 300D (DD, 240k, unmuffled hellion!)
1982 MBZ 300D (372k, retired for parts)
1981 MBZ 300D (575k, parts pig)

I'll soon be doing this on my 240D as well. I seem to recall seeing advice to replace the light bulbs in there at the same time. IIRC, there are some brighter bulbs available that can make your life better at night.

Thanks for the info. I would also like to know if there are slightly brighter bulbs that I can install while I am in there.

If you can figure out how many teeth you have.

How to repair your odometer for pocket change

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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.