You're pushing hard on what to get the gear "clicking"??? The whole car? It's probably the spur gear (s) or clutchbell thats got some worn or missing teeth. If it's in the front or rear differential then it's the gears inside the diff. You need to pinpoint where the problem is and you'll usually be able to see the problem. Use a simple process of elimination to locate the problem. As far as the grub screws working out Blue locktite properly applied will keep them from coming out. You're not doing something properly if it doesn't work.
