While I don't use any locktite on my engine bolts or engine mount to chassis bolts, I do use it on every other metal to metal connection. I even use red on the setscrews that lock the universals to the input/axle stubs. I wish someone would teach folks how to properly apply locktite though. I work on a lot of cars for other folks and i see way too much threadlocker used on at least 99% of the cars I work on. While this is a real pain, it's not near as bad as the dolts that put locktite on the steering knucke and clutch retaining screws instead of in the holes the screws will go in to.