Oopsy; OD fix almost worked.....HELP! - PeachParts Mercedes-Benz Forum

Abner Mality · #1 10-12-2003, 08:42 AM

I performed the odometer fix on my '80 300SD this past Wednesday. I followed the instructions as posted here in the group -- coat hanger, etc. Was able to clean up all the numerals, paint all my needles, and reassemble with only a few problems most of which were caused because my hands are really hams in disguise.

Upon completion, I did the requisite crowing, strutting, and back-patting until my better half blew the "okay, you're great" whistle, then I reinstalled the instrument cluster and hooked everything up.

That called for even more self-congratulation, and I then took to the road for a true test of my work. It was early in the test drive that my ego was deflated as I had no speedometer function. As I continued to drive on, it became apparent that neither the odometer nor the trip odometer worked, either.

The only positive is that the cluster looks much better, and the cruise still works. I take the latter to indicate the cable is driving the speed sensor as designed, so I have no cable problem.

Upon my return home, I went to the workbench to put away my tools and found one small, itty-bitty, white plastic gear on the towel that I had used to keep all the parts on the benchtop. This is a very small gear -- about 1/4 the size of a dime. I have no idea where it should go, but have to wonder if the gear missing from the speedo is the cause of my problem, or if MB just threw it in as an extra part. Whichever the case, I need some guidance before I remove everything and start over.

I suspect I will need a new or used speedo head, but if anyone has any suggestions that will, or might, save me that expense, I would appreciate your help.

Abner Mality · #2 10-13-2003, 12:59 PM

So far, not one response to my question about speedo repair. It's this kind of thing that contributes to my being a cranky old man.

I've ordered a used, working speedo head, so you all can rest easy, now. Wouldn't want any of you to be distressed by my simple little problem.

Sign me one old grump that hasn't allowed ownership of a 24-year-old Benz go to my head.

G-Benz · #3 10-13-2003, 01:24 PM

Sorry you got no responses...a lot of us here wouldn't crack open a speedo case...that's unfamiliar territory...at least in my case.

The usual fix is to send it off to a speedo shop or hunt for a used one in a boneyard...as you already have attested.

psfred · #4 10-13-2003, 07:57 PM

I would say you left out the drive gear, so that there is no connection between the cable and the speedo.

You really only need a little bit of LockTite to fix the odometer, just run some down to the zinc gear, wriggle the shaft back and forth to get it into the interface, wipe up all the rest of it (so the gears won't glue together, etc) and wait a couple minutes. All done.

I don't recommend that you disassemble the odo for this fix, it's way too much work!

Peter