[Mgs] MGB O/D Driveshafts

[Rick Lindsay]

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

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

>    I went poking around in the index of Machinery's
> Handbook #26 to see
> if there might be some information bearing on this
> question of length.
> While I did not find anything specific to our MG
> questions, I did
> discover that there are about 200 pages devoted to
> shafting, full of
> illustrations, descriptions, tables, etc.
>    In the section devoted to universal joints on
> shafts, which explains
> why there must be two universals on shafts rotating
> at any speed, there
> is a brief reference to couplings.  It appears that
> in shafts of about an
> inch diameter, the depth the shaft must be inserted
> into the sliding yoke
> is about two to two.five  inches for best service.  
>   Since a shaft connecting gearbox to back axle
> changes in length with
> every bump and rebound, one would assume that the MG
> engineers worked to
> keep that insertion as an average working depth. 
> And so it seems:  I
> just measured the male splines on a shaft recently
> removed from my '72 GT
> with OD.  Spline length is two inches.  Depth of the
> hole seems about
> three.  
>   For this car the shaft should be the 31.125 inch
> shaft.  Neither he
> shaft removed from the car nor the new one supplied
> by Moss a couple of
> weeks ago measured 31.125 when I did it, but there
> may be a method for
> measuring shafts that have sliding joints/couplings.
> 31.125 may be a
> nominal size, not an actual size.
>    One suspects that size does matter. Any of the
> shafts may work under
> some conditions for a while, but probably best to
> use the size fitted by
> the engineers who designed the cars. 
> Bob
> 
> 
> 
> On Tue, 25 Sep 2007 10:19:44 -0400 Paul Osborne
> <paul at ece.rochester.edu>
> writes:
> > Hi Paul,, your second line is interesting, that
> would lead you to say  
> > that then the dimensions given for sizes don't
> mean anything since 
> > we  can not figure out which one goes where.??
> > 
> > paul
> _______________________________________________
> rolindsay at yahoo.com
> 
> Edit your replies
> 
> Mgs at autox.team.net
> http://autox.team.net/mailman/listinfo/mgs