Arlene,

Check the springs.  I've had this type of noise on a few vans that had
a broken rear spring.  Look closely though.  The break is not always
obvious.

Cheers,

Jeff

On Wed, Jan 30, 2013 at 7:31 AM, Arlene K Sondergaard <asonder@usgs.gov> wrote:
> On the freeway this morning the passenger side rear wheel clunked like I
> hit a rock.
> It happened 2 more times.
> Got off freeway to look at tire.
> Pressure around 45, tire looks normal grab and shake-no give.
> The belts look OK.
> Drive the backroad the rest of the way to work for lower speeds and it
> happened  a couple more times.
> What can be going on?
>
> Thanks,
>
> Arlene
> Wolfsburg 1987 Van