Have a 2008 4421DXP. Recently replaced clutch assembly. Now when shifting to forward or reverse lever is much tighter than before and grinds when trying to engage in both forward & reverse. Took cover off, belt tension is very slight at idle. Drum/Sprocket that turns transmission is constantly turning. Should this turn even in neutral? Belt is barely riding on clutch assembly, when I hold drum to keep from turning shift is smooth and easy with no grinding. Should there be resistance from transmission to keep from turning?