I finally saw my 1st Cat 650 LE the other day at the Albuquerque Cat dealer & gave it a good look over. Without a doubt, the Front dif is not the Kawie unit found on the Prairie 650/700's but a A/C unit & has Arctic Cat stamped right on it. Same for the rear dif, as the braking is a disc & tucked way inside the right inner wheel.

 

for summer try 25w40 mercury marine oil it works good...........

 

Castrol Syntec, after breakin. I use 10W40 in the summer/ 10W30 in the winter. Purolator "PURE-ONE" oil filters.