either the left clutch wont release or the right clutch is not pulling. put it against a pile a dirt and be sure both tracks spin. that will rule out if the right clutch is pulling or not. then, while still locked up to tha pile of dirt, try to steer it both directions. compare the difference watching how the right track goes into neutral. if when trying to steer left the left track is in a bind or doesnt seem to be neutralizing, the clutch isnt being released. thats done with a hydraulic piston on side of clutch cover. could be a bunch of things causing it not to release. but this will at least narrow it down further for you.