[W126 Coupe] drive shaft to rear axle assembly

[David Fatovic]

Does anybody know how long the small spline going from
the drive shaft (or rear axle) is?  I need to take the
rear flex disc off.  I have all the bolts out.  The
flex disc was so bad that the three prongs on the
drive shaft would rotate to meet up with the three on
the rear axle.  The flex disc is completely shot.  

So now I have all 6 bolts out of the flex disc and
need to slide the drive shaft enough to slide the
desamated flex disc out and replace it with the new
one.

Can I do this without removing anything else on the
drive shaft?

David