Speedometer troubleshooting
 

Hi All,
I'm at the last leg of a full restoration of a -71T. I have just got the engine oil leak free and all the gears working so I drove it around the block.

Speedometer is not working. I bought this separate a long time ago and do not know its history. New speedometer wire.

I'm thinking of removing the wire from the gearbox and see if there is any movement on the "sender" on the gearbox when gear is engaged and running.

Do you have any other suggestions on troubleshooting? Any known issues?

Also, I got a used 15-16-17-18-19-20, as one assembly. I'm not sure about 14. Is this a loose part or a part of the assembly described? Could it be this part I'm missing not having the gauge working? Or is it just the bolt holding the assembly? The way it's drawn it looks like it goes on the end...

Thanks for any input,
Jörgen Forssling
Gothenburg
SWEDEN

http://forums.pelicanparts.com/uploa...1630753089.jpg

Have you bench tested the speedometer?

Hi All, I'm back with some information... I took the speedo out and it reacts just turning it with a screwdriver. (Turning it counter clockwise looking from the back.)

This morning, I had a look at the rear and see if the cable end at the gauge turned when I turned it half a turn at the gearbox end. No it didn't. I was also really easy to turn at the gearbox end which got me thinking. Well, the end of the cable fell into my hand... (see image)

The wire is new. What caused this? Looking at whats left of the cable I see that it is turned clockwise.

So does the gauge allow for that when reversing? I assume the very first gear I got in was reverse to get it out of my garage.

As said, does the gauge ok with the cable going the wrong way?

I now have to replace the cable. I put it in when I had an empty shell. It will be harder now of course. Can you point me to any link how to do this the easiest way. I hope I don't have to remove seats, carpets etc.

Also, I have an old cable, should I use this or get a new one? I can not say anything about its condition other than it works on the bench.

Thanks for your help.
Jörgen

http://forums.pelicanparts.com/uploa...1630834725.jpg

I had similar issue. First tried just replacing inner cable. It failed again. Second time replaced inner and outer cable. Problem solved.

http://forums.pelicanparts.com/porsche-911-technical-forum/95983-draft-speedometer-cable-replacement-instructions.html

I now know a bit more. It was the speedometer after all. It was pretty stiff to turn and it got worse quick trying to turn it by hand.

I disassembled it and lubed the ingoing shaft with some sewing machine oil. Now it is really easy to turn and it reads like it should. We'll see if I messed up the calibration when I drive but I guess a 50 year old device might have that problem anyway.

So now I want to find a replacement cable. Preferably here in Europe. Let me know if you have any suggestions.

//Jörgen

http://forums.pelicanparts.com/uploa...1630855294.JPG