95 chevy trans trouble

95 chevy trans trouble
have a 95 chevy van g20 350 with a 3 speed trans with overdrive, out of the clear blue it will not start out in first gear and will not go into overdrive never had a problem with it before. fluid is full and all electrical conections are tight, im moving in two weeks and i really need this fixed. thanks for any help in advance.

posted by  boatguy19