speedo cables

[wrx paul]

I backdated my tranny and now have a mechanical speedo instead of the 77' electric one. I installed an older speedo with the mechanical cable up through the tunnel (what a *****) and it was working. Then the cable snapped and I don't ever want to have to rethread one up that tunnel again, plus I don't know if I can with the tranny and engine in the car.
SO my very important question for you guys is...... Is there something I can do to make the electric speedo work? A small device that screws on the tranny and converts the rpm's to a electrical signal for the gauge?
If not my best case scenario would be to cut the cable and re-attach the drive piece at the gauge end since it just broke at the first 2 inches. How I don't know...

[nigel911]

Don't know about the conversion but I know what a PITA fitting a new cable can be. Reckon the cable and housing stretched when you fitted it, the cable is then 'forced' against the guage and/or tranny - leads to premature failure. Happened to me within a couple of months of fitting.

Took me a few hours to fit a cable first time round, second time I duck taped the guage end of the new cable (without the inner) to the trannie end of the old one after cutting off the nut (from the old outer housing-connects cable to trannie) with a Dremel. Keep the tape thin but cover 6-8 inches of both cable outers, then pull the new one into place by pulling the old cable through the hole in the dash once you've removed the Tach. Take your time, jiggle it a bit and should go smoothly.

Second cable has lasted so far...

Good luck.

[Early_S_Man]

There was a recent post where a VDO conversion device had been purchased that did just what you described, but no price was mentioned!

An alternative would be to mount a paired LED light source and phototransistor sensor as mfr'd by TI, Monsanto, HP, and others to the transaxle ring gear cover ... and mount a 'shutter wheel' to the CV-joint. Such conversions have been done to BMW and Mercedes cars ... in the case of a 915 transaxle, the shutter wheel needs eight slots. If your ring & pinion ratio is now different you will need to recalibrate the speedo by drilling a hole to give access to the trimpot on the printed circuit board near the back side of the case.

[CHILI]

Originally posted by nigel911
Don't know about the conversion but I know what a PITA fitting a new cable can be. Reckon the cable and housing stretched when you fitted it, the cable is then 'forced' against the guage and/or tranny - leads to premature failure. Happened to me within a couple of months of fitting.

Took me a few hours to fit a cable first time round, second time I duck taped the guage end of the new cable (without the inner) to the trannie end of the old one after cutting off the nut (from the old outer housing-connects cable to trannie) with a Dremel. Keep the tape thin but cover 6-8 inches of both cable outers, then pull the new one into place by pulling the old cable through the hole in the dash once you've removed the Tach. Take your time, jiggle it a bit and should go smoothly.

Second cable has lasted so far...

Good luck.

I did the same thing. I ended up taping my new one to the old one once I cut the end off of th old one. Chances are you probably made it turn a radious that was too tight. Probably right behind the guage. That's how my old one broke. I turned the guage so I could see how fast I was going on the freeway (Momo wheel was in the way). It was great for about two blocks then it stopped working. I found that it broke because I tried to make it turn in a radious that was too small. And I third the it's a B1tch to put a new cable in. I think I'd rather pull my motor!