I have a 2004 craftsman 18 hp LT1000 lawn tractor with a 42" mowing deck. For some reason the mower will not disengage when I release the handle. I can get it to work sometimes if I slap the handle out of the slot quickly or if I raise the deck all the way up and bump it a little. I have cleaned out any debris from around the pulley area and from around the small return spring. I even sprayed wd 40 under the pulleys and that helped a little. Any Ideas?