When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
As far as the tranny is concerned i wouldn't use anything but a good synthetic. Using Formula + or any other lube that is note designed for gear to gear contact is not good in my opinion.
Read here about oil and spiders. http://bakerdrivetrain.com/wordpress...Drivetrain.pdf
And that my friends is why Harley recommends the 5,000 mile change interval. They don't want you to wear your motor out changing oil so often. Well! it could be. LOL.