My washer will agitate and drain but the basket will not spin. I checked the lid switch and it is working fine. I can turn the transmission pully clockwise by hand and both the agitater and basket turn easily, but when it is plugged in, the pulley turns counterclockwise when agitating, but does nothing on spin cycle. Any help would be appreciated. Thank you

over the past few months mine has been toying with me, it would wash but there was a burning plastic smell (turned out to be the plastic bell thingy under the agitator) then it would agitate but not spin, then it wouldnt do either then it would suddenly start working again .... once it worked only while the front panel was off! currently it is sitting there taunting me ..... last night i took another stab at figuring it out so i took the front off, started the machine and layed on the floor with a flashlight to watch it .... it ran fine so i put the agitator back on and started it again, ran fine so i closed the lid and started it again, again just fine so i threw a lightweight small comforter in there and started it and now it wont spin, even empty. this machine is a very large thorn in my side, can anyone help?

thanks,
Jennifer