Whirlpool, WTW4816FW1, Shift Actuator keeps breaking

It stops working, it no longer agitates but it spins. The arm on the actuator moves freely on a new actuator the arm is stiff, this is why I said ““it breaks”“. When I put a new actuator on it works for a few weeks and stops agitating again. I also replaced the Pulley Clutch and drive belt.