I have a new nut (£12) and a new "the most expensive Belleville washer in the world" at £26. The flywheel took 2 minutes to remove with a £5.60 32mm impact socket from Halfords the trusty Clarke rattle gun and the Laser flywheel locking tool. To assemble the 748 factory book says 270Nm on lubed threads, the nut was threadlocked on. I will threadlock it back on but which Loctite to use, 262, 268, 270, 272, 277 or 278, also seen suggestions to use 638 but that is for gluing driveshafts and journals. My default is Loctite 270, is there a better compound?