wierd...
ya think at some point somebody pulled the brass gear from a 3.07 odo and swapped just the gear? since the speedo is the correct part # and MPH were spot on, it makes me think so... odd.
you of course pulled out the odo shaft and recalculated the lost miles since you have been driving the car right?

That's funny.

I did that twice on my first quattro, when the third odometer died I didn't re-calibrate.

__________________

Gone to the dark side

- Jeff

This thread sliped past me back in April .

Good you got her fixed.

I had a problem with our new 240. the trip would get to 10.9 and would stop. then 3 months later the odometer quit on the way to the GTG. the spedo worked fine.
I have read the Diesel Giant fix a few times, and have a PNP spedo out of a 79 300TD that I have taken apart, but didn`t get into pulling the shaft and number wheels out.

So now I have to finally fix one. the 80 240 has the 85 mph spedo, and I up graded to a 100mph spedo from PNP. well this one slips too.

Pop off the needle, remove the 2 screws on the face, and lift it off. remove the 2 screws in the back side and lift off the metal housing.
If you want to go deeper, there are 2 more screws. remove them and lift off the final part, and you will see the magnet that rotates in the cup that drives the needle.

The shaft with the brass gear that all the number wheels hang on, has a bushing on the end. I poped it off with a set of dykes, don`t squeeze the shaft, but close enough to fit under the bushing and then pry down it it will fly off .

I was in the laundry room doing this on the dryier laying on a towel. bushing flew down behind the water heater, now Iam crawling through the daddy long leg spider webs, dust lint and mouse turds. but finally found it .

I placed a piece of tape on the numbers like DG did, then pulled out the brass gear and shaft. idea of tape is so they don`t get turned and screw up the milage. gave me trouble getting it out as a unit, so removed tape and removed ea wheel and placed in a line on the towel.

used a 6" needle nose Vice grip to put ridges in the shaft for the pot metal gear to grip onto. also the VG is the same width as the gear.
then slide in the shaft, place the pot metal gear on.

there are 6 grey cogs on a seperate shaft. slide one against the PMG, then slide on the wheel with the white gear, then a grey cog, the next wheel/cog etc...

Also as the wheels are being placed, be sure to line up your correct milage.

when the last wheel is on and the shaft is through the frame, then push on the brass bushing. I set the brass gear end on something solid, and used a hammer to tap it on. be careful not to send her home against the frame or the shaft might bind.

I added the Super Glue to the PMG/shaft, and kept the assembly tipped towards the brass gear. didn`t want the glue to run down the wrong way. even then had to turn the shaft, noticed the glue was making the shaft stiff as it dried. but turning it kept it free. maybe don`t really need it.

Then it is just a matter of putting it all back together.

NOTE: it might be a good idea to lift the needle over the pin it rest against. make a mark on the edge of the face as a reference point when replacing the needle, or the needle will read fast or too slow.

Hope this helps.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Could be? There is a sticker on the back of the speedo assembly from a place in Gainesville, FL saying that it was rebuilt or repaired at some time in the past. Maybe they put the wrong gear on there when they put it back together?

I did not take the time to take it apart and match the mileage (yet). I will do that at another day. I made a note of what they both read so I can make the adjustment at a later date. The car obviously has more miles on it than what is indicated. The wrong gear made the ODO 20% slow with the 205's and it was (is) 17% slow with the 195's. At least now it is ticking off the distance properly.

The speedo and the ODO must be independent of each other since the speedo was on the money in both of them.

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AJ

1985 300D (SOLD)

The shaft the needle it attached to, is connected to a floating cup that is driven by the magnet. as the cable turns the shaft, it spins the cup which makes the needle move. there is a spring that brings the needle back to zero.

The shaft turned by the cable turns the white geared shaft, which turns the second white geared shaft that turns the brass gear.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

That is interesting and makes sense... I remember seeing "the cup" when I had the thing apart last year trying to figure out what in the hell was wrong. On the old one (the one with the wrong gearset), the speedo needle would bounce occasionally when driving really slow. The replacement does not do this? It is smooth and steady all the time.

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AJ

1985 300D (SOLD)

My speedometer started acting up, so figured I had better do something about it. I got down to the point where I started to withdraw the shaft that the pot metal gear is supposed to grip, and I had a revelation: you don't have to pull the shaft out all the way. If you pull it out about 1/4" you expose the area of the shaft that the pot metal gear is supposed to grip. I used Charlie's (charmalu) trick of knurling the shaft with narrow vise grips on the exposed part of the shaft where the pot metal gear rides. I clamped down hard with the vise gripst a couple of times, turning the shaft until I could see little indentations all the way around the shaft. They were subtle, but I knew I had hit pay dirt when I found it was VERY difficult to push the metal gear and shaft back into place. The difficulty was cause by the resistance of the pot metal gear as I was forcing the knurling into its shaft opening. I also had to make sure that the other end of the shaft was correctly centered in the hole in the sheet metal bracket at the other end. I ended up using an actual vise, with a metal spacer at the other end, to press the shaft onto the pot metal gear. Once I got the metal gear and shaft fully pressed back into the stack and poking out the high digit end that pot metal gear was on there TIGHT. I decided that the thread locker was an unnecessary risk at that point - mechanical interference was enough to keep the gear turning.

The one thing that I would have done a little different is I think I would recommend using a vise grip with a snout that is just about 3/16". Mine was a little wider at 1/4", and it seemed a little broad.

Kurt

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- '79 240D - engine swap complete! Engine broken in! 28-31 mpg! Lovin' the ride!
- '86 190D (W201-126) - 2.5 NA engine, 5 speed, cloth interior, manual climate controls, 33-34 mpg (sold to forum member).

Iam happy to hear something I added to the thread worked. good job Kurt.

After I Posted above about the 240D spedo quiting and up grading to the 100mph spedo from the 85 mph one. I stumbled across a 150mph spedo in a Euro 230E W123, with the 3:58 Diff. not a lot of these around, but have come across 4 of these in the past 2 yrs.

So I had the bright idea of putting this in the 240. now I have the illusion of going faster . also installed the 3:58, and is a 3% difference from the 3:69.


I have one important comment to make about installing the number wheels back on the shaft. the shaft with the brass gear.

Make sure the numbers line up with the window on the spedo face. this spedo gave me fits getting the numbers lined up and the grey cogs in the proper place. had it apart 4 times or so. finally get the final gear on, tap on the brass bushings and the dab of Super Glue.

Put the face on, and realize the numbers are too low. only half of the numbers show in the window .
So maybe place the face on before you drive everything back on nice and tight as you are assembling the darn thing.

Even after I knurled the shaft with the Vice Grips, the pot metal gear didn`t seem to fit tight enough. so I used a gear from another spedo. It might be the thing had been slipping on the shaft for so long, the hole wore enough not to fit tight.

After taking a few of these w123 spedo`s apart, they really are not all that mysterious and difficult to R&R.

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The thing that worried me the most about the adhesive was the difficulty of getting it to the right place (the shaft near the gear). Dieselgiant shows a small screwdriver pushing the stack to the side to get clearance, but there really isn't much clearance.

I had another thought after completing the job: if you have completely disassembled the whole wheel stack, as both Charlie and dieselgiant describe, then you may want to consider drilling a small access hole in the sheet metal that supports the shaft while the mileage wheels are out of the stamped metal bracket. The hole would need to be outside the radius of the brass gear (mark a target while the brass gear and shaft are still in place), so that you can apply your drop of adhesive to the face of the pot metal gear once it has been reassembled, and then hold the assembly in the orientation where gravity pulls the drop down to the shaft.

Cheers,

Kurt

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- '79 240D - engine swap complete! Engine broken in! 28-31 mpg! Lovin' the ride!
- '86 190D (W201-126) - 2.5 NA engine, 5 speed, cloth interior, manual climate controls, 33-34 mpg (sold to forum member).

Ok... So, I sold this car a few years ago. I was seeing it occasionally after we moved farther South. Today I saw the guy I sold it to, filling it up at the local Flying J! He said the car is great and has no real issues at all. He has just replaced all the shocks, tires and some various little things. The car now has over 330,000 miles on it and the ODO has just stopped working AGAIN! I can hardly remember fixing any of this now, but if anyone can refresh my memory that would be great. He lives only a few miles from me and I am going to offer to fix it for him this weekend since I am familiar on how to take all of that apart without breaking anything.

Seems like I remember that if the speedometer is still working, then one of the plastic gears is broken or the brass or pot metal gear is spinning on the shaft? Does that sound correct? A plastic gear will need to be replaced and the brass or pot metal gear can be re-used after the shaft has been removed and roughed up? We will also need to advance the mileage based on a rough estimate of the miles he has been driving to and from work every day. I remember doing that before... BUT, I cannot remember how I did that.

Any help or input would be greatly appreciated!

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AJ

1985 300D (SOLD)

The aluminum gear is slipping on its shaft... It needs serious knurling. I use needle nose vice grips. The gashes that puts in the shaft dig into the pot metal gear and bite firm permanently. You can add a dab of green loc tite to the knurling for even more hold...

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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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thanks for the input! I vaguely remember all of that. That is the gear right next to the brass one inside the little cage, correct?

In regards to advancing the mileage, I remember it having something to do with the little grey gears, but I cannot find my pictures or notes on that either?

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AJ

1985 300D (SOLD)

If I lived closer, I would help and bring one of my http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/336405-mercedes-cluster-gauge-needle-paint-kit.html over and really brighten up things.

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daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
No longer selling Cluster Needles Paint
No longer selling New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more

Have we determined the differences in the speedo/odo cluster that compensate for various rear end ratios. I remember on 70s era Datsun Z cars that there was a mechanism all speedo drive gear for each rear end. All that was necessary was to have the gear that matched the differential ratio. The drive gear was in the transmission accessible with the trans installed.

The speedometer in my 85SD reads low when installed in my 84. The 84SD's speedo re ads lower still. I think the speedometer is entirely electric while the odometer is mechanical. I don't know where the pickup is located.

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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 pickup is in the transmission. All mb trans have the same ratio in the trans, but the speedo is matched to the differential ratio.
Non turbo automatic or stick 240's use 3.69 rear ratio.
All non turbo automatic 300's use 3.46 ratio
All turbo diesel cars up to 84 use 3.07 ratio
The 85 turbodiesel cars use a 2.88 ratio

__________________
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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!