what you experienced is perfectly normal.
let's see.........
the differential in the rear end drives both wheels evenly............
as long as the van is going straight, and there is equal and good traction
for each rear wheel.

so it drives both rear wheels..........but either rear wheel is free to turn
more revolutions ( like the outside wheel would in a turn ) or just plan
spin.

saying that the right rear is 'the driven wheel' .......
is not true in the hardest sense of the term.
What is true, I believe is .........
due to the direction of engine rotation ( especially true in a front engine
rear drive car ) ....engine and drivetrain  torque tends to lift one rear
wheel, and push the other rear wheel downwards.

 yeah........just thinking about in my head - consider a front engine rear
drive car .......engine rotates clockwise when viewed from the front of the
engine ......or counterclockwise viewed from the driver's seat.   Viewed
from the driver's seat, the body of the car is trying to rotate  opposite
the direction of crankshaft rotation .........thus the left rear wheel is
lifted slightly and the right rear is driven into the pavement more.

this affect is also observable in single engine propeller aircraft, and in
single prop boats too. The body of the vehicle tries to twist in the
opposite direction of crankshaft rotation, and in a car that tends to drive
one side of the vehicle more into the pavement.  It's quite observable in
big trucks too .......they really tilt when the jump on the gas
...........the tractor part with no trailer attached .........with all that
torque the cab really wants to tilt under a heavy right foot on the go
pedal.

here's a trick......
the 'poor man's limited slip rear differential ' ...........when you're
stuck from one wheel spinning..............put the parking brake on half
way, or even a little more.
the idea is that by making the resistance to turning of both driven wheels
roughly the same, drive will be transferred to both wheels, including the
one not touching the ground, or slipping on ice etc.
Scott
www.turbovans.com

----- Original Message -----
From: "Brian Doss" <doss88wkndr@ZOOMINTERNET.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, April 12, 2009 5:28 PM
Subject: Only ONE drive wheel?

I have an '88 GL with a manual transmission. I got it stuck backing into an
uneven driveway yesterday. Just so happened that I was in a saddle on a
hillside, with just enough torsion on the bus to lift the left rear wheel
off the ground - and presto - no go. The left wheel spun happily in forward
or reverse. What I can't understand is that I thought the right wheel was
driven as well - why did it not receive any power? Does this mean something
is wrong with my transmission?

Thanks for any insight on the matter

Brian Doss
Butler, PA
'88 Weekender, Queequeg