tachometer doesn't count mileage
 

Hi all,

i found out that the mileage on the tachometer of my 911 SC (1980) doesn't count anymore.

Where do I have to look if everything is connected?

or what to check first?

Thnx

Do you mean speedometer? It's probably a broken odometer gear. Do a search here for broken odometer gear. There's a good thread with pictures.

It would be the speedometer and the odometer isn't counting anymore. There is a nylon gear that does go bad and you could start there and I have a new on in the package for $20 plus shipping if you are interested.

I got same problem in my 911sc -83 row .
But read there are multiple tooth count options that can and will be installed in this odometer. You will need to count the teeth on the old gear before ordering. The outside gear will have 20 teeth and the smaller inner gear between 21 and 32
Odometer Gears - Porsche - 911 76-89 (Non-US)
US spec from 1976-1989. It is a double gear with 20 teeth on the outside and 30 teeth on the smaller inner gear.

Been there done that, do your self a favor and send it to North Hollywood Speedo or Palo Alto speedo for repair and calibration. The plus is it comes back looking like new and it its perfectly calibrated. About 150....

It can be a DIY job but many send their speedo to North Hollywood Speedometer. I've done both (DYI and NHS) on separate cars. The DIY video's and instructions are pretty good but to establish exactly what you need, you pretty much have to take apart the unit to find out what the gear tooth count is before ordering. On line you'll find a company called odometergears.com that will be able to provide any gear tooth combo you need....not cheap but knowledgeable and helpful (I dealt with Darren). The original VDO gear is prone to failure due to an oil used at the factory which over time, softens the gear. Odometer gear claims the plastic used in their gears requires no lube because there is graphite actually in the plastic. Cheers

+1 on North Hollywood. I was able to repair my odometer in my Carrera with the correct gear from odometergears, but I broke the speedo needle trying to get the thing apart, none of the published methods for removing the needle worked for me. The flange on the pressed-on lens bezel was nearly impossible to remove without me bunging it up. After I gave up, NH was able to fix the speedo needle, replace the lens with glass, and press on a new bezel making it look like new. I should have just sent it there in the first place.

+1. Got mine fixed and when it came back, it looked brand new (plus it works again). I also had them reset the odometer to a specific mileage which was my estimate since it had stopped working.

+1. Sent mine to North Hollywood, installed it wrong and fried the electrics, sent it back, they fixed it again(for not a lot of money) and now it works perfectly.

North Hollywood are a great group to do business with. They even sent me a wiring diagram so I would not mess it up again. :)

Thnx, but as I have to send it from Europe, I have to look better for someone in this area