I know this has probebly been addressed before, but sorry folks I can't find it any where. I have a 2008 nightster, just did a 1000 mile lubricant change etc. used amsoil 20/50 motorcyle oil in engine and primary tranny. This machine is some what clunky on it's shifting doesn't like the original Harley oil or the recommended Amsoil 20/50 in the tranny. Can anyone recommend a good gear oil with G-4 or even G-5 rating without any friction modifyers that will work with the wet clutch in the primary and quite down the clunk or is this something I'm going to have to live with. I assume I am correct that the primary and the tranny share the same lubricant.

 

personally, I love that clunk.
I have been told it is part of owning a harley.

 

Nope, Harley recommends a completely different lubricant for the primary. Its called Formula + transmission and primary case lubricant. This is different than the 20w50 in the standard and Harley oils.

I'm not sure if 20w50 will work on not but its not whats recommended via the service manual. I just changed my fluid and adjusted my primary chain because I replaced the primary cover. I have about 600 miles but no clunking so it could be either the adjustment or the actual fluid. The formula + was around 8-9 bucks at the dealer if I remember right and it calls for 1 32 oz container.

Hope this helps.

 

Myself and most others I know that own Sportsters run the Mobil 1 75W-90 Gear Lube in the combination primary/tranny.

Many of these bikes now have well over 50,000 miles while running this fluid, and a Harley dealership mechanic friend of mine now has over 85,000 miles on his Sportster. He has been running the 75W-90 Gear Lube in his bike since day 1.

Problems experienced = 0

But nothing you use will completely get rid of the infamous Harley "Clunk" when changing gears. It's just Harley's way of letting you know the transmission has indeed shifted.

 

+1 on the Mobil 1 75 w 90 gear oil.

 

Thanks for your responses I thought about Mobil-1 75w/90 but Mobil says it has a friction modifyer in it, want this compromise the wet clutch in the primary. Amsoil recommends thier 20/50 motorcycle oil for the primary for that reason(no friction modifyers) thats the reason I used it. The Harley (so called transmission X lube was just as clunky) and the stuff looked like dino oil. However you can,t argue with success. If the Mobil-1 75w/90 that you named is in fact the Mobil-1 LS 75w/90 then I'll try it. Please confirm was what you recommended the LS synthetic

 

http://www.lube-tips.com/focus/2005_02_02.htm