Quattro driveshaft question - 86 5KTQ

[Mike Arman <armanmik@n-jcenter.com>]

Subject is an 86 5KTQ. Car was delivered to me with center driveshaft
removed and u-joint taken apart. Center bearing may have been changed,
because the 17mm head bolt that holds the yoke to the front half of the
drive shaft (the short half) was loosened.

Tightening the bolt locks the center carrier bearing. Removing the bolt and
loosening the yoke (puller required) releases it.

Here are the questions:

What's the correct torque for the 17mm head bolt in the yoke? (Not in
Bentley.)

The center carrier bearing is in a rubber "C" shaped housing - does the
open side of the "C" face the center u-joint, or does it face the outer end
(front of car) of the shaft? (Don't know if this was removed or not - the
bearing turns smoothly and silently.)

Should there be a spacer under the yoke to keep it from being tightened too
far and locking the carrier? If not, why might tightening the center bolt
lock the bearing?

I do know that the grease fitting on the U-joint itself faces away from the
center bearing, so at least THAT part will be correct on reassembly.

The rear half of the shaft has two thin balance weights electric welded to
it, but the front half has none - I interpret that to mean the front half
is in balance as maufactured, and can be refitted to the rear half either
way - "polarity" won't matter. If the front half had a balance weight, then
it would be possible to reassemble the entire shaft 180 degrees off, but
with no weights at all, does it matter?

Tired of tripping over this thing - need to reassemble it and bolt it into
the car!

Best Regards,

Mike Arman