Good thought,
I havn't found that to be a problem..
but if I was concerned about that..
besides having the body of the van solidly supported by very decent jack
stands ..
I'd support the rear trailing arms up some too , like with blocks of wood..
so the CV are running at more of a normal angle.

any time the axle between the CV won't slide back and forth easily..
or turning the rear wheels by hand with wheels off the ground is less
smooth here and there while turning ..suspect dry or binding CV's.
   These are new I gather ...I also  find dryones all the time. I put
more than the specified grease in them, and have never had a problem
doing that.
Mostly, I've had them run very smooth with the rear wheels hanging at
full droop ..but good thought or factor to considerfor sure.

On 9/9/2013 3:07 PM, Project Pat wrote:
> I was going to suggest running in the air, but I thought doing so may
> introduce some extra variables, like CV joint angle changes.
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Scott Daniel
> Sent: Monday, September 09, 2013 4:52 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Driveline vibration 87 automatic
>
> was the van run 'in the air' ..like with rear wheels off the ground (
> very solidly supported of course ) ?
>