I owned one of these wonderful A50’s from ‘76 thru ‘81 and I never had this problem. But I do have one suggestion. Have you tried just putting the rubber disk in the spinner and closing the lid to see if the spinner will operate without any water in it? Maybe that will get to operate properly again? If not, then I’m at a loss at what to do next. But I’m sure some other member may have a solution for you. Whatever you do, hang onto this little gem until you can find someone that can repair it for you. IMHO the Maytag A50 is absolutely the best portable washer for an apartment dweller.
Good Luck!
Eddie