QUOTE
Do not use copper grease on wheel nuts, as I once used it on a Ford Escort Rally car and both rear wheels fell off at the same time in the middle of a forest stage (yes a torque wrench was used correctly)!!!!!!!
UNQUOTE
Well, there's a truly empiric scientific proof from THIRTY-ONE years ago for why not to use copper grease on LandRover wheel studs! What unmitigated drivel!
We can all be very sure, the rally-car Ford Escort wheels did not come adrift (both at the same time !!) because the studs were copper-greased! If they came off as described, it is almost certain that the steel wheels were not strong enough to withstand the stresses and strains of rallying, and in 1976 I can tell you from personal experience (I was Autocrossing at the time at national level) car wheels were flimsy affairs indeed, and quite prone to such failures. There are specific reasons why they fail, due to the exact manner that wheels are supposed to fit and be secured to the hub around the wheel-studs. This system can go down the pan for two main reasons,
(1) the wheel nuts holding on that wheel have been over-tightened even once in their lives, and / or
(2) the wheels have been subjected to lateral forces and stresses beyond their design capability, such as happens in rallying and / or
(3) the STUDS stretch beyond their elastic limit, meaning they STAY stretched, meaning the nuts loosen ... and this WAS a Ford problem back then.
My advice is this -
1. ALL wheel studs should be lightly greased throughout a car's life, and copper-grease is as good as any grease, and better than some due to its ability to stay put when hot.
2. ALL wheel nuts should be checked occasionally, but MUST be checked soon after fitting (say 50 to 100 miles) and then maybe a couple of weeks after that FOR SURE, so the owner can be confident nothing is going wrong.
Over-tightening steel wheels EVEN ONCE may destroy the built-in space around the stud-hole, between the wheel and the hub, which MUST go into and remain in ELASTIC TENSION if the wheel is to stay put. If you don't understand that yet, I suggest you take my advice meantime, and start studying the principles. It is quite complicated, clever, but prone to abuse.
Please note that the wheels on the LEFT side of a car are much more likely to come loose, than the wheels on the right. This is a function of almost all cars using right-hand threads on all wheel-studs / nuts, both sides.
For many decades, lorries used left-hand threads on left side wheel-studs to reduce this very problem.
Also, be aware in NEW vehicles, that sometimes the STUDS are not fully pulled-through to fully bottomed-out. After driving a while they will settle in, and the nut and wheel involved may then run loose. In smal Ford cars way back in the seventies this was a major problem, but me being a BMC Mini man didn't care a lot about that. The more Ford wheels that fell off, the better for me! We used to enjoy watching Ford wheels coming clean off in Autocrosses complete with the brake drum and the half-shaft!
CharlesY