W123 Odometer Repair Notes - PeachParts Mercedes-Benz Forum

treiberg · #1 04-18-2010, 02:39 AM

I followed the dieselgiant write-up to repair your W123 odometer (http://www.dieselgiant.com/repairyourodometer.htm), and things went pretty well, but here are some observations that might enhance your experience if you do this and haven't done it before:

1) Use a 14mm on the main fitting when taking off the oil pressure line with the 10mm wrench. Mine was rather tight and by offsetting the torque with that other wrench, less chance of doing any damage.

2) Mine was also the slipping pot metal gear. You will know because this gear should not slip and should only turn when the main gear on that shaft turns.

3) For me, it was not necessary to remove the speedo head set as the first step to repair the pot metal gear. Not sure why he did that step.

4) Getting the pressed collar off was more difficult on mine. Required locking it with some visa grips and pulling straight out pretty hard to create enough space to get a small screwdriver in there to pry it the rest of the way.

5) Used the 7/64" bit and it worked wonderfully when pulling the shaft. Doing it this way, I had no problems at all with number alignment. Just be careful when re-inserting the scored shaft, to follow the drill bit back out, and be gentle. His article led me to believe that this was the hard part of the job. I think it may only be hard of you somehow get the wheels out of alignment (I taped my number wheels so they wouldn't move.)

6) Big mistake for me was scoring the shaft too far from the end where you are supposed to. Too much scoring too far from end meant that shaft would not slide back in all the way, because it was catching on that gear. Had to get a small file, and some steel wool to smooth out the shaft again. Insertted shaft into a dremel to turn at high RPM while gripping scored area with steel wool to smoth out again. The tolerances are incredibly tight, so just light scoring right next to that gear on the end of the shaft.

Enjoy!!

azitizz · #2 08-12-2012, 04:00 PM

I wonder why you couldnt simply put a dab of locktite on the shaft without scoring or pulling out anything else? Right at the beginning. It would save so much time and risk and would likely solve the same problem no?

ROLLGUY · #3 08-12-2012, 07:34 PM

Quote:

Originally Posted by azitizz

I wonder why you couldnt simply put a dab of locktite on the shaft without scoring or pulling out anything else? Right at the beginning. It would save so much time and risk and would likely solve the same problem no?

Trying to get any type of glue in the right spot is very tricky (if not impossible). If I remember correctly, the use of Loctite was the suggested method on the DG how-to (someone please correct me if I am wrong). I figured out (years ago) that making divots in the shaft with a pair of dikes was a better way than using any type of glue (Loctite etc.). Also, the shaft and gear would need to be cleaned first. That would mean the shaft would need to be removed anyway. Scoring (making divots with dikes) the shaft is the best way I have found. Also, using a pair of dikes to remove the collar works great (tapered sides under the collar).

azitizz · #4 08-12-2012, 09:21 PM

I see now. I just finnished the job. I didnt have any locktite on hand so I simply scoured the shaft where it meets teh first gear and it holds quite tightly. I also put on some simple wood glue on the shaft near the end (tiny bit) before I slid it back on, but by the time it got all the way in I think most of the glue came off from sliding through the housing. It could be that some stayed on but I dont get the impression that teh glue is doing much. Its the scouring that really did it.

i used a sharp tipped knife (leatherman) and it engraved nice fine lines precisely where i wanted them and it was easy to control.

I havent fired it up yet but I have every confidence it works again

ROLLGUY · #5 08-12-2012, 09:34 PM

Quote:

Originally Posted by azitizz

I see now. I just finnished the job. I didnt have any locktite on hand so I simply scoured the shaft where it meets teh first gear and it holds quite tightly. I also put on some simple wood glue on the shaft near the end (tiny bit) before I slid it back on, but by the time it got all the way in I think most of the glue came off from sliding through the housing. It could be that some stayed on but I dont get the impression that teh glue is doing much. Its the scouring that really did it.

i used a sharp tipped knife (leatherman) and it engraved nice fine lines precisely where i wanted them and it was easy to control.

I havent fired it up yet but I have every confidence it works again

Exactly what I was talking about. It is hard to make any kind of glue stay ONLY on the shaft between the gear.

Stevo · #6 08-13-2012, 10:10 AM

X2, Dropping a dab of "glue" on the shaft sounds easy till you get there

What I do sounds more scary but its not, I notch the shaft with a small set of bolt cutters. You can get the jaws right where they need to be, then a GENTLE controlled, squeeze and shaft is notched just right

. then force the gear back into position. Ive done several like this with no problem. If you screw up with the supper glue the problem would most likely be worse then replacing a gear shaft.

ROLLGUY · #7 08-13-2012, 10:18 AM

Quote:

Originally Posted by Stevo

X2, Dropping a dab of "glue" on the shaft sounds easy till you get there

What I do sounds more scary but its not, I notch the shaft with a small set of bolt cutters. You can get the jaws right where they need to be, then a GENTLE controlled, squeeze and shaft is notched just right

. then force the gear back into position. Ive done several like this with no problem. If you screw up with the supper glue the problem would most likely be worse then replacing a gear shaft.

I use just regular dikes (diagonal cutters) to make the notches. I have done many this way. I think bolt cutters would be like a "bull in a china shop" compared to making the notches with dikes.

kerry · #8 08-13-2012, 10:19 AM

Did mine about 10 yrs ago and it's still working.

funola · #9 08-13-2012, 10:33 AM

Quote:

Originally Posted by ROLLGUY

Exactly what I was talking about. It is hard to make any kind of glue stay ONLY on the shaft between the gear.

I also found it's not possible to get glue into where it's needed per the Diesel Giant tutorial.

I posted about that in 2006 not long after i bought my first Mercedes 83 300D T and came up with "knurling" the shaft with dikes as a fix, as others have done. Diesel Giant himself posted in my thread but it seems his tutorial still has the bit about using glue.

fixed my broken odometer

ROLLGUY · #10 08-13-2012, 10:51 AM

Quote:

Originally Posted by funola

I also found it's not possible to get glue into where it's needed per the Diesel Giant tutorial.

I posted about that in 2006 not long after i bought my first Mercedes 83 300D T and came up with "knurling" the shaft with dikes as a fix, as others have done. Diesel Giant himself posted in my thread but it seems his tutorial still has the bit about using glue.

fixed my broken odometer

When I first saw it, I thought the exact same thing (glue not the best way). I thought I was the first to think of "knurling" the shaft with dikes, but I did my first odo repair after 2006. I guess great minds think alike!

funola · #11 08-13-2012, 11:02 AM

Quote:

Originally Posted by ROLLGUY

When I first saw it, I thought the exact same thing (glue not the best way). I thought I was the first to think of "knurling" the shaft with dikes, but I did my first odo repair after 2006. I guess great minds think alike!

Great minds think alike is right! I thought I was the first with that idea.

Unless someone else post a thread showing the knurling idea dated before mine. I am holding onto the claim of being first.

kerry · #12 08-13-2012, 11:03 AM

I'm pretty sure I posted about it in 2002 or 3.

funola · #13 08-13-2012, 11:05 AM

Quote:

Originally Posted by kerry

I'm pretty sure I posted about it in 2002 or 3.

Post a link and you win.

kerry · #14 08-13-2012, 11:12 AM

odometer/speedometer help

ROLLGUY · #15 08-13-2012, 11:23 AM

At the time I fixed my first one, there was no definitive thread (how-to) that I could find other than the D G tutorial. Every time I see a thread about fixing an odometer, it seems that they can't find a definitive thread either (or didn't even search). Is there a how-to somewhere here? If not, I will make one with photos and step by step (sorry D G, I will not use any type of glue) instructions. Also, the D G tutorial has you remove things that are just not necessary to remove....Rich