Anyone know why my speedo jumps?

[Danspor]

My speedo won't hold accuracy I'm not sure if it is the cable or the tranny?

[Dave at Pelican Parts]

Probably the cable. The cable is also a lot cheaper and easier to replace than the tranny--or even the angle drive in the tranny.

I suggest replacing the cable first and seeing if that helps.

--DD

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Pelican Parts 914 Tech Support

A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling

[Rouser]

Considering that 914's average approx. 23K+ years-old, chances are your speedo cable is:

• Dry as paper i.e. no lube, causing it to "hang" within the conduit.
• Has a kink in it somewhere; more-than-likely near the tranny end.
• Your speedo needs attention because of 914 age indicated above.

Most of the time, it's the cable. It has to be maintained relatively straight all the way to the tranny gear drive, without a lot of "bends".

Mine does the hypnotic bouncing from rest to around 25 MPH, but I can live with that; I'll get around to changing the cable.



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Rouser!

[BenI]

Mine started jumping before it totally went dead-the problem was at the gauge end of the cable. There is a crimped-on fitting that adapts the round (essentially a long spring) cable end to a square pin that drives the speedo. This fitting had come loose from the cable. I ended up replacing the cable-kind of a pain in the ass but not too bad, but I think JB Weld couldve fixed it too. I also had the elbow drive at the tranny go on another 914, but this just made the speedo die, no jumping around. I would pull the gauge out and play with it and the cable end first.

[John Rogers]

If you have a speedo repair shop handy, you can pull the inner cable and get a replacement for a fraction of the cost of a complete cable. As you pull the old inner cable out you can feel if there are kinks and tight spots. To lubricate the cable I used some teflon based oil and poured it in the front end of the cable with a small home made funnel till it ran out the back. I did this a couple of years ago and got a spare which I still haven't had to use. Good luck.

[jmcleod]

let me add an interesting twist/story to the angle drive comment above. i thought i was being smart when i bought an angle drive at a swap meet because mine had broken. put in the new (used) angle drive and the speedo still didn't work. ??? i thought to myself. then, when time permitted further musings, i trouble shot the system and observed that the new (used) angle drive turned the wrong way! i had bought a 911 angle drive which looks the same as a 914 angle drive but you can tell a 914 angle drive as the part number starts w/914.xxx.xxx.xx