what do i put in my e maxx diff???

[rcbeast]

ok so i bought a new ring gear and it comes with the black little housing (sorry i dont know the correct term) it is where these go http://www.buytraxxas.com/product_in...oducts_id=2922 and im going to swith my gears out to the new "housing" and was wondering what i need to use to lube this area can i just use grease like i would use for the ring and pinion gear?? all info helps thanks...