kayakjr@JUNO.COM writes:

<<  I believe the correct term is 12 point internal spline recess
     driver - anyone else on this? >>

My Stahlwille catalog calls it an 'XZN'.  If you look very closely
at a new bolt head you will see that instead of 12 - 90* angles
for a 'triple square' the corners appear to be more like 85*.

My 10+ year old Wera brand 3/8ths drive tool works just fine
as its splines have worn over the years and the same holds
true for the CV bolts.

-Todd Hill
 VolksWerks Transaxles
 Olympia, WA
 360-412-0948