Ed, try to narrow it down to a particular side by sitting in the rear
seat and having someone drive you.  Jack up the van on that side and
check the wheel for play by rocking it up and down or side to side.  The
play should be either none or very small.  If you are feeling a clunk,
clunk when you check for play then you are looking at new rear wheel
bearings.  Not sure why anyone would just "repack" these because taking
these things apart to repack them is a four hour job per side.  If I
mess with the rear wheel bearings I always replace them with new.  At
290k miles it is probably about time for these if they have never been done.

Let me know if I can help you in the future.

Ken Wilford
John 3:16
www.vanagain.com

email99 wrote:
> I need some help diagnosing a strange noise.  I'm hearing a soft
> oscillating rumble with a period of about 2.5 seconds at 70 mph that
> appears to be coming from the rear of my MT '86 Subaru powered Westy.
> It's not related to the engine since it is there while cruising at a
> constant speed or coasting with the clutch disengaged.  Brakes are
> smooth and in good shape.  Wheels and tires are also in good shape and
> ride smooth with no out of round or balance shake.  Front wheel bearing
> were recently repacked with no effect on this noise.  CV joints are well
> greased and have no unusual stiffness or slop evident from moving
> half-shafts while installed.  Rear wheel bearings were repacked about
> 40k miles ago.  Vehicle mileage is 290,000 miles.
>
> Any ideas?  Has anyone experienced an actual failure of a rear wheel
> bearing, an if so, what were the noises?
>
> Thanks for any information.
>
> Ed
>