Since I changed the fluid in my trans. with the Harley brand, The old shifter clunk is even worse. I'm planning on changing to the Amsoil 75w90 this weekend. Will this quiet down that old clunk when shifting gears ? I assume the primary chain oil and or motor oil has nothing to do with this. "correct" ????

 

I have tryed several different brands all better than the HD stuff but your never going to get rid of the clunk completely. You can tone it down some but it's the way straight cut gears are. At present I am using Amsoil 75W140.

 

You are correct; the primary and motor oil has nothing to do with the transmission. I'm running the AMSOIL 20w/50 MCV in the transmission and the "clunk" seems a little less pronounced but as stated in the previous statement, you can never eliminate it completely.

 

The clunk is caused by slack in the primary chain, You could install a auto adjusting chain adjuster H.D. has one or the other brands M-6 and others are said to reduce this, I changed to redline shock proof in trans and amsol 20-50 in motor and primary and it now is smooth compared to the HD 360 and HD primary and trans lube.

 

Which Harley oild did you puty in the trans....no matter really..IMO the best oil to run in the trans is a quality synthetic gear oil (Redline, Mobil 1, Amsoil.....) I run Redline shock proof heavy, I don't hear trans noise anymore and it seems to shift smoother.

"I assume the primary chain oil and or motor oil has nothing to do with this. "correct" ????

Thats not correct...slack in the primary chain will cause the big clunk, sometimes its a double clunk..
Also check your clutch adjustment, while HD's are noted for the audible clunk when shifting, it should not be harsh..the trans should shift smoothly, its just that you can hear it shift.
Heres a good post on clutch adjustment..

clutch post