One of the CVs has a bad wear spot or spots.
The deep pits occur in the spots where the balls spend the most time.
The balls dig into the surface of their tracks under under engine load.
Every time the axle rotates while at an angle the balls move back and
forth in their groves.
The greater the angle of the axle the farther the balls have to travel.
When you lifted the van you increased the travel distance of the balls
and now they have to move back and forth fully across the old pit(s)
where they used to spend more time.
Since they are traveling more distance in the same amount of time they
are also moving faster.
When under load the balls are forced firmly against their grooves as
they follow them.
When the ball encounters the wear pit it momentarily sticks but then
abruptly launches out of the pit.
This action causes the whole axle to jump sideways.
When the axle rotates but isn't under load the balls just glide over the
deep wear pits without getting momentarily caught in them.

Mark

Vanagon Man wrote:
> This all makes sense, especially since I put on the GW lift springs recently.
> Except….
>
> Why would it stop make the sound when I take my foot off the accelerator?
>
>