OK this is my beef. I know that they hold in the pin for the hex. I see no reason to put a 'loctite' on this screw. I just spent 2 hours getting my universals in due to the fact that the previous owner decided that it was smart to use 'loctite' on these screws......
Unless you lost a wheel all this screw does is hold the pin.
Here is a pic of the old 'grub' screw and what I did to make it better. Basically I used a longer screw and 'IF' I strip it out I can use a Dremel and make a slit in the head and use a screwdriver.
New screw pics.