<VV> LH lug nuts

[Hugo Miller]

That's why I prefer to tighten them by feel rather than use a torque 
wrench - I reckon I can tell whether a nut is stiff on the threads, 
whereas a torque wrench cannot. At any rate, I've never yet lost a wheel 
or had a lug nut come loose.
And that is the problem - practically everybody I know in England 
thinks that if they fit the lug nuts dry, they will stand less chance of 
coming loose. So if they use a torque wrench, quite a bit of the effort 
will be absorbed by the friction on the threads instead of stretching 
the stud so it acts like a spring clamping everything together (not 
beyond its elastic limit, obviously). And then they can't figure out why 
their wheels have come loose.
And yet, I have watched tire fitters at truck stops in the United 
States fit a wheel to a truck with an air gun, let the jack down and out 
they drive. I once asked a fitter what torque the gun was set to - he 
shrugged and said "120 psi"! And yet truck wheels in the States don't 
seem to fall off, which I find surprising if that is how they fit them.

On 2020-03-31 00:28, Joel McGregor via VirtualVairs wrote:
> If all the surfaces are clean and the nuts are properly torqued the
> wheels don't fall off.  The problem is they often aren't clean and
> thus you have wheels fall off.
> If a stud is stretched it should be replaced.  As you said they are
> like springs and once they are stretched beyond their design they no
> longer have the proper strength.
> Torque has to specify dry or lubed threads to have any meaning
> because the values are so different.
> If torque needs to be really precise it will be listed in bolt
> stretch.  Common practice on rod bolts.
>
> -----Original Message-----
> From: VirtualVairs On Behalf Of Hugo Miller via VirtualVairs
> Sent: Monday, March 23, 2020 7:11 PM
> To: virtualvairs at corvair.org
> Subject: Re: <VV> LH lug nuts
>
> I take your point about 'bolt stretch', but if all the faces are
> clean it is irrelevant. Only if you have enough dirt, rust or paint 
> on
> the faces, and that subesquently wears off (as it will) with the
> expansion & contraction with the temperature changes, together with
> all the other forces at work - only then does it become an issue.
> I rebuilt a Kenworth W900 a few years ago, and the rear wheel fixings
> were exactly the same as my buses back in England, with the exception
> that there was no wheel spacer fitted. The idea of the spacer,
> incidentally, was that you would remove the spacer if you fitted
> thicker Alcoa wheels - saves changing all the wheel studs.
> The trouble with using a torque wrench is that most people fit the
> lug nuts dry. If you try t fit a dry lug nut onto a stud that has 
> been
> stretched by previous over-tightening, much of the applied torque 
> will
> be taken up in turning the nut on the threads, rather than stretching
> the stud. And that is an important point also - studs and bolts act 
> as
> a very strong spring, clamping everything together. The old British
> Triumph motorcycles never gave a torque setting for their big-end 
> nuts
> (con-rod bolts, that is). They specified that the bolts be tightened
> until they stretched 1/8". (It may not have been 1/8", but that is 
> the
> principle).
> I reckon I can tell by feel whether a nut is stiff on the thread or
> whether it is stretching the bolt. A torque wrench, on the other 
> hand,
> can't tell the difference. I have occasionally checked my wheel nuts
> with a torque wrench, just for curisity, and I can get them as near
> spot on as makes no difference (about 450 lb/ft is the spec). And my
> wheel nuts never come loose. And even if they did, it wouldn't 
> matter,
> as four nuts on each wheel are secured by retaining clips.
>
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