A lot of us use 15W 40W oil. Works ok for me. The clunking is caused by the clutch friction disk being stuck to the steel disk from the surface tension of the oil. The thinner ATF won't stick as bad as a heavier oil. I don't think the ATF oils the compensator good enough for the stresses it encounters. If you like you can pull the clutch in and rock the bike rearward and forward a couple of inches and it will go in first without a click. At least mine does.

 

Are you sure it is the primary chain and not just the 4th gear whine?

 

My 06 ultra classic wines in 4th gear also. The primary chain is properly adjusted and I use Mobil one 10w40 motorcycle oil in the primary and red line with shockproof in the tranny. I've just accepted it as normal and I'm glad to hear someone else has a 4th gear wine. It makes me think that it is normal for some 5 speeds. I had Mobil one gear lube in the tranny and thought I'd see if redline would quiet it down. I did help but the wine is still there.

 

It's probably coming from your tranny, not primary. Add some Syn gear lube 75w 90 to tranny and try that first

 

Mine whines in several gears but is more pronounced in 5th. 42k on the clock and whines have never gotten any worse so I am calling them normal. The 6th speed tranny (in my '07 anyway) is all straight cut gears if I am not mistaken, which I am told is what causes the whine. I initially though the whine was bearing(s) going bad, like the infamous inner primary bearing, but that I am told is more of a howl than a whine.

 

I am running mobile1 synthetic gear lube in my trans. If it is a trans noise, could it be the switch from form + to synthetic gear lube?