Using a drill I figured out that the speedo cable was broken, so I bought another and broke it testing it with my drill. I cut one of the tips off and pulled the speedometer completely out. Using the tip and a vise grip, I am unable to turn the speedo at all. I followed the instructions on PP to disassemble the speedo and can actually spin the magnet wheel, but it will not spin the square drive for the cable when the magnet spins.

btw: the needle moves quite freely, and the speed unit is completely disconnected from the odo so it can't be the odometer gears. Reading other threads it sounds like taking this apart any further isn't advised. Anyone had this problem before or have a suggestion besides sending it somewhere for repair?

Buy a different one. They're not expensive. One of the guys up in your area probably has one.

look in the classifieds, rich has a parts posting for $9.14 parts. rdauenhauer http://www.914world.com/bbs2/index.php?sho...88677&st=20

I'd sell you a used (untested) one for $25.00 shipped.

I went through several speedo cables before I realized the problem was the trip odometer. It would reach 99 miles and when turning 100 the cable would break.

It's not rocket science. Put the cable or a small screwdriver in the square hole and try to turn it. There is no mechanical between the magnet and the cup wheel that the needles is connected to. The needle moves from a magnetic field.Look inbetween the gears for a obstruction that might keep them from turning. try a little 3 in one oil on the shafts. The input goes directly to the magnet if I remember from about 10 years ago with the screw gear turning the number wheels through a gear on the end of the shaft. All mechanical speedos are the same. The 99 rollover is a little tang that comes around and turns the 1000 0 to a one just like all the other 0's. Get another one and then you can take this one apart and be educated. Usually it's worn bushings and the magnet and wheel that rubs. Or the plastic gears loose their mesh. If they get too far apart the tips of the gear teeth bind. I once had a cable that was too long and bound up the speedo. Thats pretty easy as unscrewing the cable housing nut a little will show it to get hard to tighten as it gets fully seated.

that's just it, I've completely disconnected the speed unit from all the odometer gears. the square hole will not spin. I can spin the magnet (not easily) but I assume that's just the magnet spinning around the stuck shaft that the square drive spins.

A 25.00 speedo is a lot cheaper than two 38.00 cables. Why fight it.

If you have broken the grip of the magnet to the shaft you might as well go get another one and just play with the one you have. The shaft may have siezed in the bushing but I haven't ever seen that and most of my toys are at least as old as a 914 but they also aren't as open to the elements.