no overdrive. all other drives work. on 1990 Lincoln Town Car

on overdrive what so ever engine just revs. all the other drives work fine

1 answer
It is possible that you will only need a sensor such as TCC. How ever it sounds more like the clutches, or other internal problem. We would only be able to guess here without checking it out. I believe you are going to have to take it in for diag. and repair.