Probably going to drain and fill middle and final drives in my 1980 xs850g this spring. Book calls for 80, 90 or 80w90 gl-4 hypoid gear oil. Used off the shelf conventional last tim and it worked but I'm looking at amsoil for the next one since its such small volumes. Would the synthetic 80w90 vs severe gear 75w90 offer any meaning benefits? I would think high temps and seal compatibility would be top of my list for requirements. Bike may see cool weather use but nothing like cold winter temps or super high miles between drains...
Fwiw the only reason I'm a bit reluctant to go synthetic is how many motor oil leaks popped up when i switched to M1.. AFAIK all drive units have original seals and gaskets and are leak free at this time
Fwiw the only reason I'm a bit reluctant to go synthetic is how many motor oil leaks popped up when i switched to M1.. AFAIK all drive units have original seals and gaskets and are leak free at this time