For someone who admits to no hands on experience jac mac, why do you think that the bolts have a course thread? in fact it is the opposite, they do have a fine thread. The lockwire is as you say only a safety net, I would never rely on it alone. I always Loctite the bolts as well. The other factor to consider is that the standard ZF bolts are not the highest quality, I always replace them with higher grade ones. With over 150 transaxle unit rebuilds and no failures I do feel as though I can speak with a little bit of experience! As we always say, it is the nut behind the steering wheel that is the biggest problem. remove that and you will eliminate all the problems!!