<VV> LH lug nuts

Sat Mar 21 21:21:49 EDT 2020

I agree with some of what you say but not all. You are talking about 
those square-ended studs I take it? Those have never existed in the UK. 
We have always just had one wheel nut x 10 clamping the whole assembly 
together. On my caoches, you have the drum, then a spacer, the a pair of 
wheels. The problem is not that this is too much to clamp together, it 
is that if you count all the mating surfaces from the hub flange 
outwards, that totals eight. If you have five thou of paint, dirt or 
rust on each surface, you will lose 1/16" in total when that lot wears 
off, so the nuts come loose.
I always scurf each surface with a sanding disc, then treat them with a 
spray of copper grease or cavity wax to stop them rusting with all the 
salt they use on the roads in the UK, and to help the surfaces mate with 
each other as they are tightened. I make sure all surfaces go back 
together in the same orientation they were assembled. And I grease each 
lug nut with copper grease or similar (yes I know copper grease is not 
strictly a lubricant, but it serves for this purpose). And then I put 
figure-of-eight spring clips over two pair of lug nuts. The Dept of 
Transport is paranoid over what they call 'wheel loss syndrome' over 
here, and they tell people to re-torque the wheels practically every 
other day. But they never addres the issue of good engineering practice 
or, for that matter, the issue of precession. Well, I never use a torque 
wrench - I do them by feel - and I never re-check them (once after they 
have been removed and re-fitted). And my wheel nuts never come loose.
The reason the front wheels never detach is simply because they have 
less work to do. All the rotational forces are in one direction instead 
of being continually reversed as on the drive axle. But it does indeed 
matter what threads you have, even if the nuts stay tight. Wheels flex a 
heck of a lot while they rotate, and this rotary distortion will tend to 
undo the left side lug nuts. Normally it is nowhere near strong enough 
to overcome the friction between the nut and the wheel, but it is always 
working in the wrong direction. And when you have a lot of mating 
surfaces and a bit of rust, paint or dirt thrwn into the mix, the forces 
of precession will ovrcome the friction of the nut against the wheel. 
And then you have 'wheel loss syndrome'!

On 2020-03-21 23:41, Joel McGregor via VirtualVairs wrote:
> There is an answer to the wheels falling off and it isn't LH threads.
> When the US changed to hub center wheels on trucks that isn't the
> only thing that changed.  The previous lug center system uses a
> fastener for each wheel so you only have 4 & 2 surfaces (drum + 
> wheel,
> wheel) being clamped together.  When they changed to hub center they
> went to a single nut holding both wheels on which made it have to
> clamp 6 (drum + wheel + wheel) surfaces.  Any paint, dirt, rust, etc
> between the surfaces quickly becomes too much compressible junk for
> the bolt stretch at proper torque to overcome.  With the old hub
> center system the inner wheel would be loose more often in my
> experience but couldn't come off because of the outer wheel being
> tight.  The solution is to check the torque again soon after 
> servicing
> a dual wheel.  Have you noticed it is always the rears that fall off?
> If it was just the thread direction the fronts would fall off also.
> Granted if they still used LH threads on the prope
>  r side they wouldn't fall off as often because the nuts wouldn't
> tend to spin off when they come loose.  If they are kept tight they
> don't fall off no matter which direction the threads turn.
> Nothing has changed in the design here and wheels aren't falling off
> any longer.  I'm sure proper attention to torque has become 
> mandatory.
> I carry a torque wrench on my truck.
> Joel McGregor
>
> -----Original Message-----
> From: VirtualVairs On Behalf Of Hugo Miller via VirtualVairs
> Sent: Friday, March 06, 2020 8:31 AM
> To: Byron LaMotte <bhlamotte at gmail.com>
> Cc: VirtualVair <virtualvairs at corvair.org>
> Subject: Re: <VV> Loose axle
>
> Was it a stock wheel? Left-side wheel nuts (lug nuts) should be
> left-hand thread, and on quality cars in the UK (Rolls Royce, 
> Bristol)
> they were at one time. This is to counter the effects of precession,
> which is too complicated to explain in a short e-mail, but it is the
> reason the left pedal on a bicycle will have a left-hand thread
> holding the pedal on, which seems counter-intuitive, as the rotation
> of the pedal around the shaft will tend to unscrew it. But the forces
> of precession act in the opposite direction, and they are reckoned to
> be stronger. Basically, if you imagine the pedal being very loose on 
> a
> plain shaft with no bearings in it, the shaft will tend to 'walk'
> around the inside of the pedal as it rotates, and that is precession.
> There was and still is a debate in the UK about what the government
> calls "Wheel-loss syndrome" on coaches. Typically of governments
> everywhere, instead of fixing the problem, they call it a 'syndrome'.
> Basically, the story is this; traditionally, all British-built
> commercial vehicles used conical wheel nuts (like a car) to locate 
> the
> wheels, and more importantly, they used left-hnad threads on the
> left-side nuts. So far so good. But then we adopted the European
> system of spigot-fixed wheels, using flat-faced nuts and, more
> importantly, they used right-hand threads all round. And the left 
> rear
> (twin) wheels immediately began falling off all over the place. The
> government even launched a competition to find a way to keep the
> wheels on. Idiots! All they have to do is use left-hand threads and
> the problem goes away. I did try to explain about precession to the
> relevant govt dept, but I don't think they understood it. Anyway, our
> left rear wheels are still falling off, only now it's not an
> engineering problem but a syndrome.
>
>
>  _______________________________________________
> This message was sent by the VirtualVairs mailing list, all
> copyrights are the property
> of the writer, please attribute properly. For help,
> mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America,
> http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options: 
> http://www.vv.corvair.org/mailman/options/virtualvairs
> Archives: http://www.vv.corvair.org/archive.htm
>  _______________________________________________