Transmission grinds horribly and dissengages during moderately acceleration . it started doing it in reverse only and has progressed into doing it in low forward gear and now when coasting at any speed in forward and rpm of engine drops off the transmission disengages and grinds until either completely stopped or engine speed is brought back up to match what seems to be output shaft speed or transfer case rolling speed. oil is not burned or seems to have any sign of metal or any particles in it, the transfer case oil does how ever