Mark,

From a Syncro'naught'

From my experience a whine or howl while the vehicle is in
motion and coasting would indicates a possible failure of the
mainshaft bearing.  I have noticed that they tend to 'rumble'
moreso than 'whining' but have heard both cases.  Obviously,
I can't give you a more accurate diagnosis over the 'net and
I would suggest taking it to a compentent VW mechanic in
your local area for that.  *If* it is the mainshaft bearing failing
then you should seriously consider having the transaxle rebuilt.
When that bearing finally fails it tends to allow the mainshaft
to move back and forth resulting in broken 3rd and 4th gear
sets.  The last time I priced new gear sets they were $250
each!  Combine that cost with the rebuild cost and you can
see that it quickly adds up.  Remember that this is a physic
reading on my part and you maybe hearing 'normal' type gear
whine from the trans but your local mechanic should be able
to determine that.

Todd Hill
VolksWerks Transaxles  //  VW dealer mechanic
Olympia, WA

ps- The 3rd/4th gear hub also tends to crack on these transaxles
and that can also lead to a 'whine' type noise as it loads and
unloads.