And yet another transmission clunking question!
 

I have a 1988 sportster that I recently purchased, and I have read all the post about how the clunk sound is normal but when I shift into forth (it’s a four speed) it makes different tone or pitch sound more of a clack than a clunk. Well that the best I can describe it, it never grinds sometimes I miss forth although I heard the clack sound but that maybe my fault for shifting like it’s made of glass. But it goes right in after that shifts into neutral no problem and all other gears. Anyone out there have any thoughts, also I just put in Bel Ray Sport seems a little better?

maybe those older bikes don't have the refined technology of today however they do have Harley dependability. That clack may be because you have reached the end of the gears and it's all the way up with nothing left to shift to on some kind of stopper.
I can't explain it properly but I would not let it worry me, there is no transmission adjustment per say. Make sure your clutch basket and cable is well adjusted and the tranny and primary have the proper amnt of fluids and kick that mutha into gear! It's a Harley!