Is gear the only thing that stops odometer from working?

[djcdmv]

I'm just a weekend DIYer and have read a bunch of threads about odometer repair. Doesn't look too easy, but Pelican has never failed me with all of the write-ups.

Before I tackle ripping apart the speedo, is there anything else that could cause the odometer to stop working? I'd hate to (possibly) destroy the speedo just to find out that it's not the gear. Car only has 35,000 miles on it. (It sat in my father-in-law's garage for 12 years). Thanks in advance!

Obligatory recent photo:

[javadog]

Does the speedometer work?

JR

[boyt911sc]

Originally Posted by javadog

Does the speedometer work?

JR

Dave,

I bet that the speedometer is working except the odometer. In this case, you need to check and inspect the plastic gears inside the unit. The job feels very intimidating for a first time DIYer but I assure you if you over come your anxiety about it, it is an easy project.

However, if the speedometer is not working there are other culprit/s to investigate before dissecting the unit. So what's your answer to JR's question? Keep us posted.

Tony

[djcdmv]

Sorry, speedo IS working.

[javadog]

Most likely the gears, then...

JR

[Drisump]

Like the others have said if it is only the odometer that isn't working (on the speedo),99% sure it is the plastic gear as this is a known issue with our 911's. I'm batting two for two....both cars that I own have had this problem. If you don't want to do the work yourself, there's always North Hollywood Speedo. Remove from car, box it up and send.....they must've done thousands by now. Cheers

[djcdmv]

Thanks all! Well, if I have to go through getting it out, I might as well try doing it myself. Is it true you can mess up calibration doing this repair?

[djcdmv]

Also, Pelican sells 21, 22, 23, 29, 30, and 32 tooth gears for an '85. Any idea which I need?

[djcdmv]

Nevermind... 20x30?

[Cevan]

I just did this as a new 911 owner. I bought the gear before even taking the speedo apart. Very satisfying job to complete.

I used this thread for guidance.

1. Use a small screw driver to start to remove the trim ring. I did the lower half and was able to pull the ring off. Go real slow and just bend a little at a time. Really take your time.

2. I pulled the speedo needle. Mine had a mark at 0 mph. I turned it past 0 and lighty pulled up. Then I went the other direction until it hit the limit and again lightly pulled up. Back and forth a few times and it popped right off. I went about 5 extra degrees past the limits when turning.

3. I put painters take around the face and removed the two screws holding the face on.

4. From there, it's just a matter of taking the guts out and separating the mechanism from the rest of the speedo. The above thread has lots of pictures.

5. Getting the trim ring back on was a little time consuming but again, go slow.