A small amount of grease mist or greasy dirt around the wheels can be fairly normal, especially if the wheel bearings were packed generously from the factory, but it should not be constantly pushing grease out heavily on both sides. Those thin dust caps are usually not true seals, so excess grease can work its way out once the bearings warm up during taxi and landing rolls. It’s worth pulling a wheel apart to confirm the bearings were not overpacked and that the caps are seated properly, because too much grease can create heat and force its way past the caps more easily.
