GE washer no spin when loaded

About two weeks ago it started having problems with the spin cycle not working. My wife found if she removed some of the load then it would run the spin cycle. It has gotten worse day by day and now will run the spin cycle with no more than a very light load in the tub.
I looked at the washer today found the agitator works, the washer drains but will not run the spin cycle unless the load is very light. When the washer is loaded and the spin cycle is not working, the motor hums and gets hot. I thought maybe the starting capacitor was bad, but it seems to ohm out properly. Also checked the transmission for binding it rotates easy when the brake is relased.
My last thought is the motor, but how would I test for a weak motor?
I also bypassed the door switch and the water level switch and that did nothing to fix the problem.
Any other ideas would be great.