My experience was the same except the sound would not go away at high
speeds.  I would raise the rear wheel, turn it both ways, feel the clunk
(notice the shaft may move inward when it hits the clunky spot) and know it
is a CV joint.  You don't list your odometer reading but it's a safe bet
the CV is due for some attention.  The job is not too difficult but you may
run into two different types of bolts that hold the joint to the hub (the
star pointed bolt vs. the hex head bolt).  If you do one side, better do
the other cause it won't be far behind.  Refer to Bentley.

Jeff Birk
'89 Wolfsburg GL (Road Whale)
'82 MB 240D (Slo Mo)

>I have heard some talk of CV joint making noises in the past.  Recently my
>2wd auto 86 gl westy has developed a knocking sound eminating from the
>left rear of the vehicle.  The sound increases in tempo as the van's speed
>increases.  When going fast it is hardly noticable (high tempo, other
>sounds drown it out?), but it is really noticable when just starting out
>on a cold day.  Any ideas?  Is it CV joint wear? how do i check them?  Any
>advice would be greatly appreciated, I'm a newbie but i promise i will try
>to answer other's questions when i have gained some more experience.

 TIA,
 Andrew Fox
 86 GL Westy