Your best bet is to get a joint with the fitting in it when the sealed units fail. The so called lifetime or sealed units have a thin nylon disc in the bottom that that the ball pivots on with the grease. If you drill through the metal cap & damage the nylon disc it will fail & now you have metal on metal, it is just a matter of time before the joint will fail & you won't get much more life out of it. The OEM's design them with a limited life span contrary to their lifetime designation they give them.