Temporary fix if your splines are shot is to drill and tap 1/4-28 through the lever into the shaft for a set screw. Not a permanent repair but it could get you through for a while.

 

On a 2010 road glide my lever is tight on the trany shaft by not all the way seated against the trans. Should a loosen the bolt and slide it closer or just leave it. THANKS

 

the bolt passes thru a groove in the shaft to keep it from moving in or out
you cannot slide it in farther or tqake the lever off without removing the bolt totally out of the lever unless either the bold or shaft is messed up