When moving machines for alignment, always use jackscrews. If you don’t have them, beating on the machine frame with a steel-face hammer is a lousy idea.
First, you run the risk of damaging the bearings, seals and other delicate components in your machines. Secondly, you have little control over the magnitude of your moves. Thirdly, it’s unprofessional. If you don’t have time to weld or screw on jackscrew assemblies, consider using a couple of carpenter’s pipe clamps, tensed against each-other. This makes for a handy portable jackscrew arrangement that is safe, inexpensive and offers you plenty of control. If this is not possible either, and you must hit the machine with a hammer, then at least do so with a plastic-face, shot-loaded deadblow hammer.