CV joint clunking is the result of lack of lubrication combined with the inner and outer sections wearing or getting divots  from the forces of the pressure being applied between the parts and the balls.
On the tranny side pressure is applied from the outer part to the balls to the inner which then turns the shaft. On the wheel side the shaft turns the inner which pushes on the balls pushing the outer section which then drives the wheel. So simply removing a shaft and turning the assembly around the forces will still wear the same surfaces. Taking the shafts and swapping from left to right side will wear the opposite side of the ball slots. So will removing each joint and turning it around. On automatics the shafts are different lengths so the joints will have to be moved. 

On Syncros looseness in the joints will eventually cause other noise problems and due to the f our wheel interaction the joints will wear in both directions. If they are loose and sloppy and noisy replacement is the best option. 

Dennis
 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of J Stewart
Sent: Monday, April 18, 2011 8:38 PM
To: vanagon@GERRY.VANAGON.COM
Subject: CV Joint Question

Hi Folks,
My issue started out as a shudder on acceleration, but last night I noticed a clunking sound as I rounded corners, so I'm guessing thats my CV joints crying out for some attention. Its been many years since I've dealt with CV joints, I replaced them on a Bay Westy I had, and I remember it was days before I could get that awful smell of CV joint grease out of my head. Funds are a bit tight right now, and I'm hoping to get away with just cleaning and repacking with fresh grease. My boots are in good shape, no cracks or splits. I seem to recall being able to swap the CV joints around and getting double the life out of them. My question is, is that taking the right side and flipping it around on the right side, or moving the right axle to the left side and left side to right? Seems like the same thing to me. TIA, Jeff

Jeff Stewart