91 transmission

[blkmrideon22s]

i just got my 91 explorer out the shop bout a month ago.the guy at the shop was suppose to change my transmission fluid and the transmission fluid is still black. for the last 2 weeks when i stop at a stop light i can hear the transmission making a whining sound but if i put in neutral the sound stop. well i went to work yesterday and my explorer was running fine but when i went to leave it start acting up. when i take off it doesn't seem to change gears and i can go over 35 mph and if i try to go faster my tach start to red line. can i fix this by change my transmission fluid or has my transmission gone bad?

 

[Gadget X]

I'd try changing the fluid and filter first, also check your modulator valve on the transmission. It's located on the passenger side, just above the heat shield. There is a vacuum line that goes to it. If you pull the vacuum line off and there is transmission fluid in it, then it's bad. Good luck, and I'm sure someone who knows a little bit more about the trannys will chime in if I missed something!