[dirty4man]

are u sure the noise is coming from the diff. The front diff takes gear oil not grease. There is a filler plug on the left side of the diff. to check fluid levels. You also may need to inspect the wheel bearings and CV shalfs, the noise you hear may be coming from either of these.

 

[dirty4man]

First thing to do is check your diff fluid. more than likely it's going to be the wheel bearings. Just jack up the bike, grab the tire on top and bottom of it. Try moving it back and forth, you will know if it has slack in it. As long as the boots are not busted, filled with water and sand or the axle is not flopping around in the cups. you should not have any problems with them.