If you decide to do a change, be sure to flush the axle with some kind of solvent, and drain it well before refilling. I use Diesel fuel as a kind of universal solvent for things like that, since it's a little bit oily, and doesn't completely strip the lubricant from moving parts. To fully drain things, jack up one wheel at a time and let the lube that's in the hubs and axle tubes run to the center. Then refill with fresh lube and jack up the hubs again to flood the wheel bearings with oil.
Jerry
