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924/Early 944 Odometer Fix

Disclaimer: any information provided here is used at your own risk. I accept no responsibility for any damage you may do to yourself, others or you car. Having said that I thoroughly recommend getting yourself the Haynes owners workshop manual for the 924 or 944. It's the best publication of it's type for the car, oh and also make sure you're on friendly terms with your local porsche parts interpreter and wrecker, they can save you both time and money with their useful information.

Fixing that broken odometer/trip meter
I've lost count of the number of cars and stories I've heard about broken odometers in the 924 and early 944's. The fix is quite easy. It involves removing the Speedometer (quite difficult), opening it up (quite easy) and supa-gluing a little plastic gear (dead easy!). The example I give here is from my experience with my car (a '77 right hand drive) it should be the same for most other models.
You'll need: 1 phillips head screw driver, 1 small flat bladed screw driver, small hands (not like mine!) and lots of patience!
1) Sitting in the drivers' seat reach under the dash with your right hand. Locate the back of the tachometer and gently push it out steadying it with your left hand. (It'll just pop straight out).
2) The tachometer has three wires attached to the back as well as two light globes. Remove the two light globes by just pulling them out (now is a good time to replace the bulbs!). Pull off the three wires taking note of which pin they come off (there are four pins!) on my car they black, blank, green and brown (looking at the back of the tacho from left to right) brown is intrument earth, green is feed direct from the distributor and black is (I think) another earth (DO NOT CONFUSE the wires!)
3) Remove the two phillips head screws securing the dash surround, but don't remove the surround, you only need to be able to move it a little.
4) With your right hand through the tacho hole gently push out the speedo a short way. This should be enough for you to feel around and unscrew the speedo cable (it may be tight!).
5) If you can't unscrew the cable don't worry, next remove the wire and three globes from the back of the speedo. (one brown earth, two illumination globes and one indicator globe).
6) With your left hand under the dash feed the speedo cable out while pulling the speedo out with your right hand.
7) Unscrew the cable now if you haven't already.
8) The speedo should now be free, work it out of the dash (it may be tight!)
9) Using the small flat blade screwdriver prise off the lip around the speedo bezel, don't worry if you bend it you won't see it from the front.
10) The bezel comes off with a "snap" and with it comes the glass (plastic!) and another seal.
11) Remove the two screws on the back of the speedo and work the mechanism out of the case.
12) The broken plastic gear is located on the end of the shaft holding the odometer numbers. If it's still there you can just supa-glue it on the shaft. Check before you glue that it's all working by turning the cable drive and confirming that the numbers are going around. I found that moving toward the end of the shaft worked quite well.
13) Reassemble by reverse order.
14) Replacing the speedo is quite tricky. I found that the following worked best for me.
-Work the speedo back only a short way into it's hole so you still have access to the back.
-Attach the left hand globe and screw in the cable.
-Push the speedo back in (but not all the way) I needed to guide the cable with my left hand from under the dash and push quite hard (it's a VERY tight fit)
-with the speedo almost home, woking through the tacho hole, I put back the indicator globe, the earth wire (brown, goes on a pin on the speedo body) and then the right illumination globe (you changed the globes right??)
-Push the speedo firmly home.
15) Before putting back the tacho confirm the lights and indicators are working:take care that no tacho wires are shorting when switching on the ignition!
16) If all is well replace the tacho taking care to put the wires back in the right spots, and push it home
17) Replace the dash surround and retaining screws
18) Fire her up and go for a test drive!

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