My buddy has an 07 Duece that makes a loud noise when he changes gears. It is not the usual Harley "clunk" that we are all used to. The best way I can describe it is a loud "metal slapping" noise...."Twaaank!) When he shifts it's like the bike is being forced into gear. I can hear it good when riding behind him form a good distance. Any thoughts??

 

Anybody ever seen or in this case heard this???

 

Primary chain too tight??
Nobody ever heard anything like this???

 

So my buddy that owns the Duece called me while servicing his bike a couple days ago. Last time he serviced the bike he went with the same combo I use.
Amsoil 20w/50 synthetic in the engine
Amsoil 75w/90 in the trans
Amsoil Supershift synthetic in the primary.
He tells me when he drained the transmission it was really thin and had a red tint. He is thinking when he changed fluids last he put the Supershift in the transmission? This stuff is essentially automatic trans fluid. Could this be the cause for the noise? He put the 75w/90 in the trans but it is still making the same noise. When he changes gears it sounds like whacking a anvil with a 2 pound hammer...very loud and sharp sounding!