I went riding last weekend and fell into a monster mud hole. Mud up to the top of the engine. Its a 06 rincon 650. Twice while giving it gas to get out it seemed to pop out of gear. Once the quad was finally out of the mud we just sat for a couple minutes to laugh and joke about it. When I put it into neutral and started it up all was fine. When I tried putting it into drive it was just grinding, no engagement what so ever just a grinding noise. I tried reverse and there was no problem. So i went from reverse to forward pushing strait threw neutral and it went in, with a little bit of grinding but it went. Now just to clarify, this machine has been meticulously maintained no problems since purchase. I was NOT rocking forward to reverse in the mud. I only gave it good throttle going forward. This happens in 2 or 4 wheel. I have read that the motor oil is transferred to the transmission, could this simply be that the oil lost its lubricity due to oil cooler being unable to get fresh air. Or did I break something.