My washer will fill and aggitate but will not spin . What could the problem be?

The coupling between the motor and transmission is probably bad.

Mine did that and there is a safety switch to make sure the lid is closed before it will go into the spin cycle. Wait for it to fill and agitate and then open the lid and look for a latch or little switch on the lid or latch area. I just pressed mine and kind of held it down "permanently". It isn't safe but cheaper than getting a new one :/