Hi, All instructions say when removing hub nuts that one has to buy a new nut each time, they are called one shot nuts, does one really need to do this as the nuts I removed were as tight and stiff to put back on temporary), the nut looked perfect in every way, Why not reuse these and perhaps use some locking fluid as a precaution, I cannot imagine a nut that is torqued to 290 NM + is going to fly off by itself, the rotation of the wheels would even prevent such a thing happening. Is this simply one of those super safety measures and does something happen to those nuts if they are reused, and yes, I know the threads are slightly distorted on a new nut but as far as I can see this stiffness still works on the old nuts.
If the manufacturer states you should use a new nut then I would assume they do so for a reason, in this case probably safety.
Is the risk of the wheel coming off really worth what you would save just for the sake of a nut, how much do they cost?
its a shame they never used a castellated nut with a split pin.. when i first got my old-ish van one of the first things i attempted to do was remove the drums and have a proper look inside..
i could not get those silly one shot nuts off so the job didnt get done.. it went on the jobs to do list and its still there.. he he
Quote: Originally posted by trog100 on 29/4/2019
its a shame they never used a castellated nut with a split pin.. when i first got my old-ish van one of the first things i attempted to do was remove the drums and have a proper look inside..
i could not get those silly one shot nuts off so the job didnt get done.. it went on the jobs to do list and its still there.. he he
trog
The reason why they used to use a castellated nut with a split pin is because the wheel bearings were the taper roller type which you set up with just a bit of free play to allow for friction and heat expansion from the rotating bearing. The bearings are now in a straight ball cage thus require need no setting up but the one shot nut has a nylon spigot incorporated in the centre which grips the thread on the stub axle, and because it's the only part involved to stop the nut coming loose it has to be torqued up really tight. When the one shot nut is removed, the internal nylon spigot is worn so no longer can grip the thread which is why a new one shot nut is required. One thing is for sure, if you reuse the one shot nuts and the wheel comes loose causing damage or a collision involving a third party, your insurance is never going to pay out on that one. It's amazing how many people don't know the science behind the technology and become ignorant to safety just for the sake of saving a few bob.
The One Shot nuts are also known as Clenched Nuts, there is no nylon inside any of the old nuts I have removed, if you look at the outer side the hole is slightly out of shape with two marks on opposite flats hence clenched nuts, I have one in my hand now which I keep for matching up when buying replacements.
Quote: Originally posted by Vectratot on 30/4/2019
The One Shot nuts are also known as Clenched Nuts, there is no nylon inside any of the old nuts I have removed, if you look at the outer side the hole is slightly out of shape with two marks on opposite flats hence clenched nuts, I have one in my hand now which I keep for matching up when buying replacements.
Yes you are absolotely right as I remember my service engineer showing me now about 5 years ago. I was thinking of nyloc nuts which do more or less the same thing but probably the application is for threads with a smaller diameter.