Classic/Antique Car Repair: 1963 Ford drops out of gear, xl 500, detent

Question
My 1963 Galaxie XL 500, 352 engine, automatic on column, drops from Park to
Reverse without warning or any contact with shift lever, especially when running
in park, but occasionally when the car is off - it just doesn't go or stay in park
well and it's unsafe. What can I do to repair this?

Answer
This was a common problem with that era Fords. Ford fixed the problem with an insert for the owners manual advising the driver not to rely on park but to be sure to set the parking brake. There is a detent in the upper steering column for the shifter and when it wears the problem is worse.
Brad