Loctite 660 will Not harden until it is contained in a space with no air, it is a heavy paste, and can not be used between 2 surfaces that must move against each other during operation. ... You can use it on a keyed fixture like you have pictured. Are those 2 pieces both keyed on the same shaft? if so then yes you could use it between them. It almost looks like there is a slot machined to hold a seal or thrust washer?
660 is good between a bearing outer surface and a case, or a bearing inner race and a shaft. But never inside the bearing itself...
660 will occupy & fill any void when applied it will shape itself to any space, then with the lack of air, it hardens, But it is not an adhesive or locking compound... if needed, you can later disassemble, clean up and reapply when reassembling.
:smile:KennyV