Is anyone running synthetic oil in the front or rear diff, if so hows it working and what weight of oil. I have a 450es and in the winter its a little stiff to move up here in Canada

 

we've used amsoil 75-90 in 4 quads now without 1 problem.take a quart of gear oil and a quart of syn.gear oil and put it in your freezer overnight,the synthetic will still pour almost the same and the other stuff will be like tar