GMC Repair: gmc 91 sonoma,standard5,4x4, freeway, sonoma

Question
Driving on freeway last night,could'nt put into 5th. I can now go to 2high and then into 4...I felt a vibation and heard a high humming right when "it" happened , but nothing now.   What could it be? Shifting fork maybe? I was told it had a rebuilt tranny about 60000 miles ago, right now it has 220000.

Answer
hello jill
this could be a bad shifting fork or a bad pressuier plate i would have it checked out by a tranny shop . to make sure but that is what it sounds like . if the tranny was rebult the right way it shoud of lasted longer . good luck to u hun and you have a pretty name pete