Question:
We are a very small company so to keep the cost down for repair work we like to do as much as we can for ourselves. We have noticed increasing backlash in one of our ball screws and would like to repair it. Could you give us some pointers on how to approach the task. Is it necessary to replace the balls if they look OK or can we simply adjust it somehow?

Answer:
Many companies do all their own repair work quite successfully and there is no reason why you shouldn't do yours. As I have said before, repairing ball screws is not rocket science, but it does take care and patience and a little skill to obtain a satisfactory result.
First, it will usually cost you a little money but it will cost you a lot more if you screw up.
Second, if it doesn't feel right then it probably isn't.
Third, if you are not sure what you are doing, leave it to a professional.
Fourth, single ball nuts are more difficult to preload than two piece ball nuts because they are preloaded using the correct ball size.
Fifth, never use the old balls.
Sixth, always do the preloading on an unworn part of the screw.
Seventh, good luck.