David:
Yes, you are overlooking something. The principle involved is
centripetal force. The threads are handed so that the knock-off will
tighten up while moving forward. You still have to install them
reasonably tightly in the first place (see manual), or the wheel wobble
will keep the knock-off from tightening properly. They should NOT loosen
with use - definitely not in my extensive experience - unless the
splines are shot. If the splines are that bad, they should be replaced
ASAP anyway.
Extended (a mile or two) towing backward WILL allow the knock-offs to
loosen and fall off. I had this happen on a Healey 3000 back in the
'80s. The towing company (duh!!) had to cough up for a replacement front
hub (damaged when the wheel came off), new front fender/splash panel and
paint job (ditto), new wheel/brake rotor (ditto), and new knock-off
(never found). The other front knock-off was nearly off too.
The only other loose spinners that I have ever had were on a
newly-purchased MGA back in the late '70s. I got it halfway home
(several miles), felt the front end acting loose, and noticed that the
two front spinners were just about off. Not very much further and the
wheels would have been jammed in the wheelwells or rolling off down the
road without the car. Turns out that the DPO had just done the wheel
bearings and accidently swapped the hubs side-to-side.
Dave Q.
As and Bs
>From David Pennington:
> I am not trying to be obstinate, but why would a spinner get tighter from
>driving the car forward as opposed to backward? Stopping and starting torques
>have been discussed. My experience has been that stock spinners tend to
>gradually loosen with use. I also know from experience the stock setup can and
>will unscrew if the splines fail, and I have proposed a theory as to why they
>do so. But what possible force could be twisting the spinner if the splines
>are not spun? Am I missing something here?<
> <snip><
> I don't follow your reasoning here, and would very much like to understand if
>there is a mechanical principle I am overlooking.<
>
>> ------- Original Message -----
>> From: Dave Quirt
>> David:
>> Don't do it. To do so is a definite death-wish. The main draw-back is that
>extended reversing WILL eventually unscrew the hub-nuts when they are on their
>proper side - they tighten (or keep tight) during forward motion. If put on
>the wrong side, they will be reversing whenever you are moving forward. Get
>the picture now??<<
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