[Mgs] MGB O/D Driveshafts

[Bob Howard]

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