Hmm... I hadn't thought of that! We bought an aluminum gear but haven't installed it yet. I was going to apply some synthetic grease just to be safe. Has anyone had any issues after using a metal gear? My assumption had been that the plastic wasn't quite up to the heat level and/or heat cycles, in which case the metal should be better. When the plastic gear fails, does it always revert to 2WD (as our '08 E83) or sometimes to AWD? If using a metal gear and something else jammed, would it do the same (2WD vs. AWD) or the opposite?