Original Grey Technic motor from 1977: 6216a

[Jens Bauer]

the assembly you want is already present:

http://www.ldraw.org/cgi-bin/ptdetail.cg.../6216a.dat

similar ones for the variants should be created analogously

I created 6216a - it was actually my first submission...

The reason I posted the above, was that Magnus suggested we separated the axles from the main body, so we'd see a complete motor housing without the axle. This has the advantage that you can rotate the axle in any position you wish (to make teeth of gears fit nicely).

... But I think I understand what you're saying ... eg. having a fully assembled motor of each variant.
These motors use the "body assemblies" (which Magnus suggest being the main housing + the back) and then you can pick which axle you want to use, plus you can rotate the axle as you wish.
Most axle/body combinations would be valid anyway.