Janet, at the very minimum your should remove the rear hubcaps ( or all 4 )
and check that all lugs nuts are tight. It can be an extreme mistake to
assume that people put things back together properly.  It's the opposite
actually, you should assume that some might not have gotten things back
together properly, sorry to say.
    It does sound cv-joint-ish, or that certainly pops into mind. BUT the
van was just worked on, and that's where any investigation should start.
Please check those lug nuts and rear axle nuts !!   
  I just paid 500 dollars to have AC hooked up on a subaru vanagon, and they
left an AC hose out of a bracket and almost in the rear spring.  It happens.

Scott
www.turbovans.com 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Janet Sanford
Sent: Sunday, December 23, 2007 4:37 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Clunking knocking sound

Thanks for all the responses - I thought it may be a CV joint issue - but
wanted to be sure.

At first I thought it had something to do with the brakes, but it was making
that sound before I had them done.

I appreciate all the advice as I hate going to the repair shops clueless and
fear getting taken!!

Janet