Dave:  I hope Tom Carrington's observation applies in your case......

I had this problem ~40 yrs ago [good heavens!!] with my Sunbeam
Alpine.  Had approached it by putting a Bungee cord on the shift lever
once I got on the highway.  This worked OK until the time came to sell
the vehicle; then repairing was not optional.

Would have been a killer on my student budget, except for the kindness
of Dad's friend Charley, who at that time worked in the Baltimore Fire
Department repair shops.  I learned about pulling transmissions, then
Charley did the rebuild.....  I still think about him when I see the
Sunbeams at British Car Day.

Hope your luck now is as good as mine was then!  Usual apology for
Vanagon relevance.

Glenn
Queenstown, MD