Chrysler Repair: 92 t & c speedometer goes wild, cv boot, vertical shift

Question
I have 92 T&C (voyager) 3,3 AWD and the speedometer goes wild and cruise control fails to work.Earlier the speedo jammed on 80 km/h but knocking on the meter helped.Jamming hapened after driving sometime.speedo goes wild at first but starts to work after appx. 10 km`s.

Answer
Hi Jari,
That behavior suggests that the speed sensor on the transmission is faulty. I am uncertain about exactly how the speedo signal was obtained in '92 because things were in transition at that moment. The '91 approach was to get the data from a "distance" sensor mounted on top of the transaxle extension housing (box out of which the half-shafts extended),while in '93 the speedo got its data from the output speed sensor on the front of the transmission very near the end of it, just to the right of the vertical shift rod. I suspect the former is the source in your '92 because the transmission is not mis-behaving, which it would if the latter were flakey. Also, the former sensor is subject to being damaged if a mechanic errs by pulling out the right side half-shaft to repair a cv-boot without first removing the distance sensor. That may be why you are having this problem. In any, case the sensors cost around $75 and you can replace them yourself. I would replace the distance sensor if you have one on your transmission.
Roland