Broken Odometer
 

My odometer not only quit working one day, but it managed to add about 600,000+ miles to itself! I would have noticed this if I was driving it, so it must have been when someone else had it.

I read Clark's write up and it seems very detailed. I found one broken gear. It is the gear that the worm gear turns. The write up seems very descriptive. I am stuck on #12; "Gently pry up on the speedometer needle to remove it from its shaft. " I tried with reasonable pulling force by hand to pull it off. I did not get crazy on it as I don't want to break it. It still works! :) Any ideas on a better way to get it off or can this thing take a good pry without damage?

I am not able to move any of the gears. They all seem to be locked in place in both directions. I am guessing that maybe something broke off the broken gear and landed in the gears somewhere binding them. Any ideas there without it being apart yet?

Thanks!

Yep, break that pin that the needle is on and you can throw the speedo away.

lol... thanks for the comforting thought! :)

Could take the screws off the face plate and carefully take the screws out with the plate on. It would be a PITA but it is doable.

Any other ideas that do not include throwing the speedo out? :)

My needle came off with a good tug - no issues.

Use a magnifying glass to look into all the gears. You should be able to see where the gears are jammed. As for removing the needle a cheap plastic door removal tool with a V cut into it will help. You might have to file it down to fit under the needle shaft. GENTLY pry the needle loose. Go slowly, no need to rush doing this. When you install the new gear put a tiny drop of super glue on the shaft where gear is in the proper position. I hope this is a help for you.

Cheers,
Larry

Cheers,
Larry

I actually tried to replace the drive gear on the speedo without removing the needle. I read somewhere that could be done by taking loose on the faceplate and working carefully under that. Funny thing is that the loose face plate made the needle come off! So it worked well for me. Just be very careful and apply even, steady pressure.

I can get the two screws off for the face plate itself. That leaves me with about 5mm to work on the 4 screws below. I will work on it that way in hopes that the needle will fall off on it's own. :)

you probably got it off already, but when i did mine, i gently pried it up while turning the needle counter-clock wise. once i started turning it, it came right off.

Will turning the needle counter clockwise damage anything?

I put the gauges back in the car. It only takes me about 5 minutes to get them in and out now. I am getting pretty good at it. Only 10 easy screws to get it out. :)

it didn't for me. when i put it all back together, it all worked fine. i thought i read the "counter clockwise turning" tip on clarks-garage.
mine, and 88, doesn't have a pin ( to stop the needle at 0mph), so i was able to turn it. if you have a pin (i think the earlier models do), then you won't be able to do that.
When you put it back on, just make sure to put it on so it rests at 0mph again, and you should be fine.

I took my needle off with a flat tip screwdriver (i think) when I fixed my odometer a while back. The next timeI took the needle off I broke it, but superglued it back together. I did a write up on it. http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/417996-speedo-odometer-problems.html hope it works and GL

I ended up sneaking a jewelers screw driver in the side to get the 4 screws out from under the face plate. I am going to guess that the PO may have glued it on.

When I got it apart I found the top set of gears, the gears that spin each number, to be out of order. Each one of these gears has an alternating fat and thin gear. The gears all have to line up here, fat all the way across. Mine were mixed and it caused the numbers to lock up when they tried to spin. This in turn broke the gear that the worm gear turns when they locked and the motor kept spinning. I will order that gear next week with a couple other parts. This took a fair amount of time to get everything to line up and work properly.

Upon putting the speedo back in with the rest of the gauges the two thin wires broke from the speedo unit! I was worried now. Very thin wires, very tough soldering points, and no real room to work. Fortunately the two leads into the speedo were long. I went to Radio Shack and bought 22 gauge wire and heat shrink tubing. Having bad luck soldering in tight places before I thought I would try the shrink tubing. I cut the wires back, over lapped the by about 5mm, and used the shrink tubing to hold them tight together.

The shrink tubing is working. Assuming very minimal movement and the tight shrink on the wires I think I might be OK here.

Thanks for all the input and help!