I recently went through a long series of diagnoses as to why my diesel
westy, in addition to the usual diesel noise, had this loud drubbing and
whoom-whoom-whoom sound on the road that pretty much drowned out the diesel
noise that I pretty much have under control now.

I took it to one place, they said it was the tires. I took it to my tire
placee they said it was a right front bearing. I took it to my vanagon
shop, they said it was my right rear.

I went so far as to buy a full set of rear bearings and deals, which I am
glad to have as spares, but I am glad I did not spend the money nor do the
work to replace them. It wasn't in the rear.

If I swerved to the left, it made the noise louder, making everyone think
it was a right-side bearing.

Low frequency sounds cannot be located by the human ear, I should have
remembered that from messing with audio equipment.

It was the inner bearing on the left front. I replaced the bearings and
races this afternoon and am enjoying the silence.

Jim