[Healeys] schuttle shake

[Bob Spidell]

Mark,

The phenomenon known as the Healey "scuttle shake" occurs consistently (usually) 
between 55 and 60mph when driving on smooth roads at steady speeds.  It is most 
noticeable (or only occurs?) in the 6-cyl cars which have a longer wheelbase 
than the 100s.  It appears to be due to a harmonic in the chassis.  The whole 
car shakes where, for instance, an unbalanced wheel is usually felt in the 
steering wheel on in the seat of your pants.

I've done most of the recommended procedures--including balancing the driveline 
and the brake drums--and still have a bit of the shake in my BJ8.  This over 2 
sets of wire wheels, several sets of tires and numerous truings and balancings 
(including 'on-the-car' balancing).  Some claim good results from immaculately 
trued, balanced and rounded wheels; e.g. from Hendrix (unfortunately, wheels and 
tires don't stay trued, balanced and round indefinitely).  I can't vouch for 
bracing the transmission tunnel and adding additional spot welds on the scuttle; 
I know several people on the List have tried it but I don't recall one coming 
back and declaring 'the shake is definitely gone.'  I suspect any and all mods 
may help but none will eliminate it completely (and permanently).

I've learned to live with it.  If nothing else, the shake informs me when I'm at 
55mph if I'm having speedometer problems.  My car is smooth as silk above 60mph.

Bob



Mark LaPierre wrote:
> Just checking to make sure that you are kidding here Alan.  My 
> understanding the
> shake phenomenon is just that,  a Shake.   My car isn't on the road yet 
> so I am assuming
> that the cars do actually vibrate at a certain mph if the anti scuttle 
> operations are not
> carried out.
> 
> It is interesting however that I have never experienced this shake with 
> other LBC that I have
> had out on the highway.   Wonder why the Healey drums seem to be this way.
> 
> Anyone?
> 
> MARK
> 
> 

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Bob Spidell           San Jose, CA            bspidell at comcast.net

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