Question. Does the tub spin in the same direction when you're trying to wash as it does in spin? If so, you may have an issue with the timer contacts controlling motor direction being stuck in 'spin'. Also try leaning the machine back and turning the trans pully by hand. It should spin in one direction and cause the agitator to move in the other. If the tub wants to spin in a agitate direction or spins by hand without any pully turning, you might have a brake package issue or there might be a leak/moisture issue that's not allowing the tub assy to 'drop' and engage the brake. The brake works by the pully turning in spin up a cam and pushing the tub assy up against the internal spring and the unit spins. when the washer stops, the pully comes down the cam (which is part of the lower trans drive shaft) and the brake spring pushes the pads against the brake housing and stops the tub. Try having some one hold the spin tub and turning the trans pulley in the agitate direction to see if the trans will agitate at all. What you find will help us with a better course of action. Good luck.
RCD