Plymouth Repair: transmission, coverter, senser

Question
when my van was at the speed of 77 to 80 km there was a vibration. it seem that the overdrive was shifting. this week end i was pulling my boat and the transmission would not shift in high speed.
what could be the problem.

Answer
Hello Dom
this should go in to a tranny shop so they can look at it it could be as simpile as a shift senser .

or a tour coverter and it could be the worse as a bad tranny pump which would mean tranny rebuld.

Most tranny shops hace free diagnostiacs test .

Good luck to u and if you need more help let me know
please rate my serivice

pete