Hi, we recently re-installed the engine/transmission in my car and I've noticed my father-in-law used Permatex Low-Strength threadlocker (Purple) on the torque convertor to flexplate bolts, rather than the Medium (Blue) or High (Red). The bolts were all torqued to spec. My question is has anyone had bolts come loose after using the low strength stuff? He would have also used it on the flexplate to engine bolts which is lot harder to fix than the torque convertor bolts. I realise now we should have used the blue (hence my question), but what does everyone reckon?