Odometer Gear replacement for Electronic Speedometers (long)

[198491132]

Excellent, just finished my fix. Great write up and thanks.

Two hours to get the original bevel edge free, the hardest part of the job for sure. 20 minutes of work, and done. Back in the car and running. Total time was 3.5 hours. Careful with cleaning things out. Blow out with air and use rubbing alcohol as directed in the original text.

I wrote the mileage on the speedo with a sharpie, letting the next owner understand the marks left on the unit from behind.

Needle came off with the back and forth past stop motion describer.

Dave

[Discseven]

Damm nice doc & pics Craig! (My question was how to get the face off the instruments and you covered that nicely.)

[Discseven]

Originally Posted by Discseven

Damm nice doc & pics Craig! (My question was how to get the face off the instruments and you covered that nicely.)

... Only in my case slowly & progressively prying the face ring off doesn't work. Can't get enough leverage --- or face ring is perhaps age-welded to case. 1980 vintage here.

[sus911]

No luck for me either. I made a special clamp tool to try to prise the ring off but no go.
I ended up giving it to a great local instrument repairer who did it for me, checked the whole thing out & tidied up some nicks I put on the ring trying myself - $120, very reasonable.

[lespaul]

Subscribed. Putting this on my list of things to do this winter.

[rokemester]

This is a tremendously helpful thread! I was able to swap out this damaged speedo gear while watching the Browns beat the Buccaneers this afternoon.



It's a wonder it lasted this long! The damaged gear was brittle and sticky like it was decomposing. Why is this the only gear that wears like this? The other gears seemed OK? Thanks again!!

[rokemester]

...forgot to mention that I was able to "recalibrate" the speed indicator using the back and forth tightening motion. Now I'm within a mile or two of GPS. Nice.

[peppy]

Thanks, worked like a charm.

[xhfty]

I wonder what it would take to get the individual that repairs these for Pelican to chime in on how they handle the speedometer needle removal problem?

[TheSt|G]

Originally Posted by xhfty

I wonder what it would take to get the individual that repairs these for Pelican to chime in on how they handle the speedometer needle removal problem?

It's not a problem if you do the "pass the stop" method and aren't hamfisted with it.

[CHICKS]

xhfty is a spammer.....

[TheSt|G]

Originally Posted by CHICKS

xhfty is a spammer.....

Crap.

And get out of my mom's house.

[Cevan]

This thread is great. Just repaired mine with a new gear from our host. A couple of observations:

1. I pulled the speedo needle using the above suggestions. I went back and forth about four times, from min to max and when I hit the stop, I turned the needle about 5 more degrees and gently pulled up. When it finally let go, it really lets go so be careful. It takes very little pressure to reinstall the needle.

2. I put tape on the face surrounding the two small screws to protect the face itself from my screwdriver.

3. I put everything back together but for the bezel and trim ring just to confirm everything worked.

4. The tenths on the tripometer have a white background and were dingy looking so a Q-tip and rubbing alcohol cleaned them up nicely.

The whole thing took less than an hour. A very bright headlamp and reading glasses helped immensely.

[SpyderMike]

I just did mine today. Took about an hour.

I thought I might add some pictures of the hardest part (in my opinion)...the removal of the bezel. I use jeweler screwdrivers to wedge between the the case and the bezel in a twisting motion while slowly working my way around the case:



When I was all the way around, I used several to work a section over the lip:



and the widest blade one with blade perpendicular to the case and pulled it around the circumference:



Then the bezel came off.

As others have mentioned, I marked the needle's stop points min and max:



Then I slowly worked the needle as suggested. After about 6 times back and forth easily and slowly without much force, the needle came off.

Unsoldering the ground wire would definitely make the interior work easier. My gear was like chalk and just crumbled in my hands.

I used a medium flat blade screwdriver to press the bezel edge back down...pushing perpendicular to the case and then rolling it down tight. It takes quite a while to work you way around the bezel. Take care not to stress the reset plunger while doing this.



I installed my LED lights and put the gauge back in the car. A quick drive confirmed success:



Time to move on to vinyl and carpet installation.

[1990C4S]

Nice steering wheel.

[rockryno]

is this the gear? 20x30

Porsche Odometer Gear ODOPOR2030 - Odometer Gears - ODO-POR-20-30 | Pelican Parts

[rokemester]

Just make sure it matches up with your model year. It makes a difference. Good technique on removing the bezel in previous post. Just take your time. Good thing to do while you watch a baseball game.

[rnln]

Guys,
My odometer and trip meter both stopped rolling recently, after I reset. The thing is that I don't remember if I reset while driving or not. My speedometer is still working. Do I have the same problem/fix as Thrasher?
Thanks.

[198491132]

Rockryno that is correct ...for my 84.

[Drisump]

Yes you do. The claim is that it typically happens while reseting while in motion but the gear is so brittle after all those years...it will happen, babied or not. I didn't use the VDO replacment gear, after the same issue happened on my second 911, I sought out an alternative. I bought the gear from odometergears.com. They claim the gear is made of a product that is self lubing. I have read in another source that the lube used at the VDO factory eventually breaks down the gear...perhaps this is true since this appears to be an issue on all VDO equipped cars of this vintage. Cheers