Removing Odometer Gear Pinion - PeachParts Mercedes-Benz Forum

Diseasel300 · #1 11-27-2016, 10:46 PM

I'm sure I'm not the first person with this problem, but finding a definitive solution is getting old fast.

I have my cluster out and taken apart and need to get the brass ferrule left behind by the dissolved odometer pinion gear off the shaft, but that sucker is STUCK STUCK STUCK!

I've tried pulling it off with pliers, tried heating it with a soldering iron to loosen it up, tried prying with a screwdriver. That sucker's on there. Any tips to get that thing off of there without ruining something expensive?

Diseasel300 · #2 11-28-2016, 04:09 PM

Squeezing around on the brass pinion with a pair of dykes got it off. The area under the brass ferrule was fairly rough, no wonder it wouldn't come off.

optimusprime · #3 11-29-2016, 06:41 AM

All this you will find in DISELGIANT 123 SPEEDO REPAIR .

tyl604 · #4 11-29-2016, 09:29 AM

Yes, as I remember the instructions when I repaired mine on a 1981 300SD said gently squeeze it with a pair of dykes and it will break apart. That worked for me. Without those instructions I would have had no idea how to do it.

Good luck. Mine has worked fine since.

Junkman · #5 11-30-2016, 01:25 PM

Here is a link to a source for gears. Gears - Designatronics Inc.

Does anyone know what the gear specs should be? I know that the center hole is 2mm. My 85SD doesn't turn and the gears are shot to the point where teeth can't be counted.

renaissanceman · #6 11-30-2016, 01:48 PM

Hello all,

I have a very high end 3d printer that can make the gears you need for the speedo as a much lower cost than the above company.

Send me the specifications and I'll make one for you as a favor

funola · #7 11-30-2016, 01:55 PM

Quote:

Originally Posted by renaissanceman

Hello all,

I have a very high end 3d printer that can make the gears you need for the speedo as a much lower cost than the above company.

Send me the specifications and I'll make one for you as a favor

What material can you make the gear in? I have one made of Delrin which has a crack and is loose on the shaft because of the crack. By spec do you mean detailed dimension drawing or can the gear be copied by scanning?

renaissanceman · #8 11-30-2016, 03:29 PM

I can make it in an ABS analog (a UV cure resin). Delrin (especially the cheap old-school acetals), while a great gear polymer, is a pretty poor material for pressing onto a shaft. It's too brittle for that application and will crack with age.

Drawings would be great, but not really necessary -- a couple of good photos, basic dimensions of center bore diameter, number of teeth, outside gear diameter and total length of the gear will suffice.

I'm a capitalist, so I'd end up making a small run to sell off on the forums for a reasonable price to cover my costs.

Cheers!

Junkman · #9 12-01-2016, 11:36 AM

I'd like a 2 sets. One for now and one for the next car that has a non-working odo.

Is this information enough for you to make them? It looks like there are some variations.

Odometer Gears - Mercedes-Benz - S class (126) 79-91 Diesel

My 84 SD has a working odo. I could count those but the speedometer is off and I don't know that the odometer is correct.

renaissanceman · #10 12-01-2016, 02:14 PM

Oh, the gears are already available?

Diseasel300 · #11 12-01-2016, 02:36 PM

Replacement gears are available from several sources. What needs to be known when ordering is what the tooth count is for accurate/reliable counting.

The drive pinion is always 12 point. Second gear is usually a 12/48 point. Third gear varies. Some are 12/48, some are 16/48. My '86 SDL is 15/48.

If you have the wrong ratio on the final gear, your ODO count will be wrong as well.

Junkman · #12 12-02-2016, 11:43 AM

Quote:

Originally Posted by renaissanceman

Oh, the gears are already available?

Only at inflated prices that reflect the fact that generic gears have been determined to work for a specific Mercedes application.

I expect that you could sell some if you put sets together and had a way for people to easily determine what set is needed.

Alternatively, provide 1 each of the gears that are common to all of the speedos. Include 1 each of the variations and people could use a GPS to get the correct set up. That set would be more convenient in that people wouldn't have to dismantle the cluster to count the existing gear teeth and could wait until ready to install.

JamesDean · #13 12-02-2016, 10:25 PM

For what its worth:

OdometerGears.com is the best source for these things. I've never had any problems with them and they'll last pretty much the until the car rusts away. Sure the are expensive relatively speaking but its a one time purchase.

I've had customers ship me other gears that listed being applicable to the car in question only to find that the gear just spins on the shaft and does not mesh like it should.

I measured the diameters of the gears and they were off by 2mm or so. I've got pics on imgur somewhere but the site isn't loading. Evidently I made a video for my customer: https://www.youtube.com/watch?v=EPgU7GMExGs

For the 85SD, from OdometerGears's website, this is what I ordered.
Mercedes-Benz -US 126 Diesel Three Odometer Gear Set - with 15 inner tooth count, so

E1 = 12
E2 = 48x12
E3 = 48x15

Diseasel300 · #14 12-02-2016, 11:09 PM

The gears I picked up for the SDL came from a site called Garagistic, total cost with postage was just over $20. I can't comment for the longevity since I only got the gears today, but the material is the same as the 2 plastic gears that drive the ODO wheels, size is perfect, and they mesh and roll smoothly without any slop or catches. If they take a dump and die, I'll follow back up in the future with how long they lasted. For the cost, I can buy several sets for what Odometergears wanted for their set (likely of the exact same gears).

JamesDean · #15 12-02-2016, 11:18 PM

Quote:

Originally Posted by Diseasel300

The gears I picked up for the SDL came from a site called Garagistic, total cost with postage was just over $20. I can't comment for the longevity since I only got the gears today, but the material is the same as the 2 plastic gears that drive the ODO wheels, size is perfect, and they mesh and roll smoothly without any slop or catches. If they take a dump and die, I'll follow back up in the future with how long they lasted. For the cost, I can buy several sets for what Odometergears wanted for their set (likely of the exact same gears).

I'm glad they worked for you. Those pink gears that my customer sent me didnt (as you can see in the video) now this was on the 85 SD. Maybe they didnt pick the right gear for it and assumed it was the same as other SDs I dk. I know I had two sets of gears from Garagistic, both for 85 SDs now that I think of it.. Neither worked.

Finally got imgur to cooperate:

Original MB:
http://i.imgur.com/AA8Uk6A.jpg

Garagistic:
http://i.imgur.com/Y3zWV4b.jpg

OdometerGears:
http://i.imgur.com/42GeUHd.jpg

For what its worth, OdometerGears has their own injection molding machines and makes all their own stuff (at least the ones that I've bought).

You said the gears you got were the same material as the others? Were your gears pink like mine in the picture? Maybe whatever issues I ran into they've resolved? Or I suppose it could be limited to the model car I was working with.