6x4 Gator torque converter/ transmission trouble

Hi everyone. I just bought a gas(Kawasaki) powered 6x4. When I bought it, the idle adjustment screw was backed out so far it wouldn't idle without a little pedal assist. I now know why...when idled up it won't go into gear...tranny growls and grinds. Could the torque converter be engaging at too low of an RPM? This is what it seems like, as if I idle it back down, and pedel it enough to barely keep it running, the tranny engage, but it still grinds a little. Should the pulley on the transmission be turning at idle, and if so, how fast? As soon as the engine starts, the "bell" on the engine pulley snaps in on the belt, causing it to turn the pulley on the tranny.

Any help would be GREATLY appreciated.

Thanks,
Randy