[Mgs] MGB O/D Driveshafts

[Rick Lindsay]

Fascinating.

A few years ago I restored a 1930 Chevrolet.  It was
fascinating to see how many strange engineering ideas
where employed - ideas today that are NOT considered
best practices (e.g. bearing lubrication by oil
dripping).  In the '30s there was a lot of
experimentation.  For me, that's part of the
restoration fun.

My dad, now deceased, used to say that we are loosing
technology as fast as we are gaining it.  And while
that statement is probably not strictly true, his
example was quite good.  He asked, "Pick any 10 people
off the street and ask them to start at first
principles and make a lead pencil."  Could they do it?
 I mean, do they even know that pencil lead isn't
lead?  That it is graphite and clay?  What is graphite
and where do you find it?  Can you make paint for the
wooden sleeve?  Can you even make the wooden sleeve. 
How about finding iron ore and smelting the metal for
the eraser holder?  And where do rubber trees grow
anyway?  

You get the point.

That to me, makes older technology as fascinating as
new technology!

Best,

rick

--- Bob Howard <mgbob at juno.com> wrote:

> Rick,
>   I don't know why they use the flex discs, called
> Cardan (maybe it's
> Cardin or Carden?) joints in France and England. 
> They were used on
> Bugatti 57(replaced one on a friend's car years
> ago), I remember, and you
> see a lot of them in inboard engine motorboat
> applications.  Perhaps they
> can take a certain amount of thrust that the U-joint
> should not take. I
> don't know--it's just a guess. 
>    A shaft supported by a center bearing can be
> smaller in outside
> diameter than an unsupported shaft of same total
> length, and the center
> bearing can alter the speed at which it gets a
> "whip" (critical speed). 
> My Chev S-10 pickup used a two-piece driveshaft
> connected flange to
> gearbox, shaft, support bearing, flange,flange, rear
> shaft, flange, axle.
>  My Toyota Tacoma, slightly larger & heavier but
> with less weight
> capacity, uses a one-piece driveshaft with "lubed
> for life" u-joints. 
>   One supposes that, within limits, different
> designers just do things
> different ways. 
> Bob
> 
>   
> On Tue, 25 Sep 2007 08:01:17 -0700 (PDT) Rick
> Lindsay
> <rolindsay at yahoo.com> writes:
> > Most interesting.  I wonder why the Italians and
> > Germans use flex disks (guibos) instead of
> u-joints -
> > or in addition to u-joints?  It is also a classic
> > repair for older BMWs to replace the center
> > drive-shaft bearing.  Do they use center supports
> > because of lighter shafts?  Or are these just
> quirks
> > of design?
> > 
> > rick