Welcome to the site odan, you are probably just adding to much diff fluid? I have heard of guys filling it to the full mark and having this problem. What you need to do is measure out the correct amount that it states in your owners manual and only add that amount. Good Luck.......Irv
The grizz 600 and the kodiak are famous for this, it is a known yamaha boo boo. Heres what i did on my old 600. About six inches from the diff up the line, cut the line and put in a vacuum hose adapter from the size of the hose to bigger then to the size of the hose again. This creates a pocket for the fluid to get into and the hot air will bubble through thus not pushing the fluid out. I have done this on numerous kodiaks and 600 grizz's and never had a problem again.
A forum community dedicated to Yamaha Grizzly owners and enthusiasts. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more! Open to all Grizzly models including 700, 660, 600, 350, and 125.