Loose front in Carl Zeiss Distagon 2.8/21 ZE T* Canon...Nikon,, etc.

The problem with the loose front in Carl Zeiss Distagon 2.8/21 ZE T* for Canon...Nikon or other camera brands. It's acctually "easy" to fix, just unscrew the nameplate with a rubber tool, and then loosen the 3 BLACK SCREWS around the the lens group, NOT the 3 screws around the shiny alluminium front ring. Next step, the 3 screws that sit in the front part is loose, then take 1 screw at the time and use a drop of screw lock (Locktite 243) on the thread on each screw.., THAT's it. Then assemble then lens again. Cheers Kenneth