OK, bottm line: what is better for the clutch / tranny , the book specified 10w -30 type SE OR transmission fluid? With all the stresses and complex parts in an automotive automatic transmission, it seems to me that automatic transmission fluid would be a better lube to use for this application.
LOTS of info on this topic already. But long story short, give it a shot, it won't hurt. I ran it in my KX250 for 2 years and NEVER replaced a clutch (changed fluid once a month--Type F ATF---cheapest I could find at WalMart). I had no problems at all. Some complain it causes their clutch to drag...but seems to only effect certain bikes.