1976 Chevy K20 – Tranny Failure

Hi again everyone. Well if youve been following my other posts you may know about my history with the truck so far. Tonight I was trying to go to the store and I let the truck warm up but when I tried to put it into gear nothing happened. I could feel the notches and it shifting via the linkage but I couldnt get the truck to go in reverse or drive and the engine wouldnt go into a lower idle like the tranny was engaged if that made sense. I could hear and feel the transfer case so I knew that it was working. I revved up the engine and at one point the truck tried to pull forward but then it just stopped. I tried selecting reverse which always worked before without any problems and got nothing there either any suggestions? Again its a 1976 Chevy K20 with a 400 sbc and a TH350/400 tranny (automatic). Last thing I did to it was finish bleeding the brakes yesterday and it drove home just fine after that.

Im not sure if its related or not but from time to time when I start it the radio and wipers arnt working but it I shut off the truck (key to off posistion) and restart it the radio and wipers are working again