What gear oil do you use?
 

Hi, I have a 2009 Wolverine 450 that I am going to do a fluid change out on. As far as gear oil my manual says use GL4, and I understand that GL5 can attack brass parts. I would like to use a full synthetic but I don't know what gear oil folks reccomend. I see some in the store that just say GL5, like Mobil 1, and also some that are GL4/GL5 like a Valvoline product. Would the GL4/GL5 dual rated stuff be safe in the machine? What do you guys reccomend?

I work for Exxon Mobil. Just use anybodys full synthetic. I use Mobil 1 20W50 V Twin and Mobil 1 mx4T 10W40 for winter time.

sorry just realized you wanted gear oil. I use our Mobil 1 synthetic gear oil. You can get it at Auto zone I beleieve its a 85W140