I'm not totally familiar with your specific type of ball screw but....I am in the middle of an X2 conversion and I have re-loaded my balls a few times. It takes some practice but its not rocket science. If you are missing balls you can measure and get replacements. I would replace all the balls with ones from the same supplier. That way you can be sure that they are indeed the correct size. I have bought some replacements from VBX but ebay is a good source for odd sizes.