olefirebird

I purchase a 1982 firebird 4cyl auto tranny. What happens is sometimes I hear a bit of a squeel while I drive which didnt seem to affect anything. Now sometimes in the morning I put it in drive and the transmission doesnt engage and when I push the pedal I just hear a squeeling noise and I barely move. Then if I put it into reverse I can feel it engage (sometimes engages hard) then go back to drive and im fine. Some days I have issues some days I do not. What do you guys think?