I need the help of the collected wisdom of the Vanagon group as I have a
never encountered before problem.
My van is a 1988 Westfalia with 152,000 miles.

When attempting to back out of my parking space this morning, the van
would roll about 5 feet, then stop.
It felt as if I were hitting a curb or one of the wheels was chocked. I
could move forward with no problem to the limit of the parking space,
about 6 feet,
but in reverse the van would consistently stop.

I had recently worked on the brakes, so I thought that perhaps I had
neglected to tighten something, but a visual inspection showed nothing
out of place.
Then I tried rolling backwards in neutral. While I could roll back a
little bit farther than while in reverse, the van still stopped.
The transmission has been working fine with no problems shifting and no
noise.

Can anyone give me suggestions on what to look for and what it might be?

thanks,
Todd