Going to help a friend today with his rt1. Said it locked up in second gear or some gear. Just thought I would ask what to look for in the outside cases. Im a little familiar with the at/ct shift set up but the rt appears different. I did print the dt manual off the site and assume the piston port dt/rt and the same bottom end.

He said oil leaked out and we pulled the front sprocket cover and the little plug below the clutch rod fell out and seemed to be where the oil leak was. Hoping maybe the trans got a little dry and warm as it seems  to shift turning wheel on stand. What should I seal it with, just some rtv.

Maybe locktite it in as never needs to be removed. Just put it in flush. Check he's not drained the oil out the detent underneath, be sure plunger & Spring are still there or will muck up trying to change. If it's cause by 'no oil' then may be damage but I'm sure he'd be looking for a cause before a litre of oil went on the shed floor. Be a slowish leak as selector shaft is a pretty good fit. Otherwise you'll need to get at the selector drum end behind the clutch to see if it turns or if the change arm has escaped the pins. Yep total different setup to you AT or CT.

It seemed to shift through the gears turning the rear wheel. He forgot his key but I sealed that small plug back in and we will see next time we get to work on it.

Motor will run if you unplug the switch but if the key is around it's best to wait. I'm just impatient.