IMO, Jay's wrong about engaging the OD 'under power.' After rebuilding my OD--which I had engaged like that for over 30 years--I realized that if you do, the cone clutch is engaging under load, hence prone to slipping a bit and wearing (new clutches are not available, best I've seen are rebuilt from DWM). I put the clutch in a couple inches, then hit the switch, and let the clutch out, and there is never a 'clunk.' Note Jay didn't know the name of the OD manufacturer.