83 Chevy 4X4 with the 700R4. Place shifter selector in Park position all appears to be fine.
Shut engine off, remove foot from brake, vehicle freely rolls.
Happened a couple times over the last 3 weeks.
When it rolls no clicking sounds, acts like it's in neutral. Stomp on the brake, move selector to reverse than back to Park. All is well.
Linkage, linkage bushing, broken spring somewhere? About 200K after a major rebuild.
Rebuild was routine no surprises. Hasen't been abused. Suggests what to look for.