hi all im new here. im a dirt biker comming over to the other side so far so good!!
just got a bruin4x4 , love it , but i was riding on the ice 1/2 to 3/4 throttle and i had some
rear diff fluid come up the breather tube and drip a small amount out onto the air box
is this normal ? thanks Rich

 

I have saw that problem a few times, mostly on Wolverines though. I have came up with a couple of answers, one is that the diff is slightly over full. The other is that the extra grease that I always pack into my bearings could be getting in to the gear oil. The last time I changed rear bearings and oil I flushed my diff case with diesel fuel. Put it up on blocks and ran it to stir the diesel through the diff well then let it drain for a long time. Filled the diff untill it ran out the filler hole with quality hypoid gear oil. I am not sure if that is the proper fill level or not. I need to check to make sure. But anyway mine seemed to quit blowing the oil out after that. I have seen other Yamahas do this. It was never a major differential failure or anything of that nature. Hope this helps you out some. And by the way welcome to the forums.

 

thanks , i love this thing