lwa60aw

replaced brakes , replaced pump , drive belt , helix plastic and drive pulley , helix and pulley do not hold ,it disengages brakes and spins but not the wash tub helix stays still and dr. pulley hops over and gets damaged lubed shaft .dont know if that was a mistake . the shaft the helix and pulley is connected to has a up and down motion is this a problem with the trans mission