Speedometer went out on my van about a year ago. After doing quite a bit of
trouble shooting I isolated the problem to the transmission. This problem
became particularly aggrevating because it was intermitent. After a while it
became a solid problem and this enabled me to get a handle on it. I had
suspected everything from the speedometer to the gears in the transmission.
After pulling of the tail piece I discovered the gears were in good
condition. Problem was the gear housing,. the little plug of metal the cable
screws to on the tranny. It was worn and this was allowing the gears to
seperate. Anyway I didnt let all of this troubleshooting go to waste. New
speedo gears new seals in the tail piece new U joints, new gear housing. Oh
yeah. when you pull the gear housing about 2 quarts of tranny fluid is going
to drain out.