Ben,
Part of the answer is in your nearest Engineering Dynamics text. Visualize
yourself in a moving frame of reference, ie travelling with your car at a
steady speed down an endless highway, and observing the right front wheel.
The wheel is turning clockwise, and the knock off is also turning clockwise.
In order to sustain its angular momentum in a clockwise direction, a
continuous (albeit small) force must be exerted on the knock off by the hub.
If the knock off were a right hand thread, this rotational force relies only
on the friction of the thread, and if that friction slips, the knock off
would spin off. Hence the use of a leftt hand thread on the right side .
Repeat the visualization for the left side wheels, and we conclude a right
hand thread is required. Braking will tend to loosen knockoffs, but
subsequent acceleration will tighten them again!
However, the TD/TF thread question baffles me completely!
Cheers,
Nigel
46 TC 0710
73 Triumph Trident
> -----Original Message-----
> From: lbprince [SMTP:lbprince@email.msn.com]
> Sent: Saturday, September 23, 2000 7:06 AM
> To: mg-t@autox.team.net
> Subject: Thread Direction
>
> As we all know, wire wheel knock-offs on the left side are right-hand
> thread
> and those on the right are left-hand. These orientations supposedly keep
> the knock-offs from loosening, particularly with heavy braking.
>
> Per the Workshop Manual, the axle nuts on the TD/TF are a different story.
> The left-front nut is left-hand thread, and the right-front nut is
> right-hand thread (page K.6). Both sides on the rear are right-hand
> thread
> (page H.5).
>
> Aside from dismissing it as being "typically British", does anyone know
> the
> reasoning for all this?
>
> Ben 54 TF 1500
>
>
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