Well, forget the breather vent. The breather vents for our transmissiosns
terminate up into a special little hose which is routed way up into the
engine compartment so that no contamination can enter the trans. Unless this
hose is cracked or come off its perch (unlikely) you have nothing to worry
about the breather vents. 

Many 4x4s do not have this feature and so they have to stop after a deep
water crossing and examine the oil in thier trans to see if any water enterd
their transes through the breather vent. Us syncro vanagon dudes can be eating
 out of our fridge while they do this dirty job cause our vans are made by
Styer Daimler Punch, who thinks heavy duty.

 Another thing to check is the breather vent for the trans-
>   axle - If this has become clogged with grunge or mud [been out
4-wheeling?]
>   the pressure increase inside the gearbox when it heats up may drive some
>   oil past the seal.

Dave, thanks for the insight regarding the breather vent. I wasn't
aware that such a vent existed so tonight I'll check Bentley to see
where it resides.

Drew