Transmission blockes in Park

[Belgium R/T -68]

My 904 tranny blocks with the shifter in park from time to time and it's not the shifter itself. Any idéas?

[RD]

not sure what you mean by the term "blocks".  can you further explain?

[Belgium R/T -68]

It's a -70 ebody. The slapstick gets stucked in Park, when I disconnect the lever I know it's inside the tranny and not the shiftlever/slapstick.

[John_Kunkel]

What is the history of the transmission?  In some cases the park rod that extends from the VB into the tailhousing gets swapped for the wrong one, the 904 and 727 rods are not interchangeable and if swapped will cause binding.

In some rare occurances a misplaced snap ring allows the park rod to get wedged between a snap ring and the housing; this is the snap ring that holds the ramped plug in the tailhousing. If it's clocked wrong, there is just enough room for the rod to get misplaced and jam up.

In the pic below the snap ring is properly clocked as far clockwise as it can go and the lower end of the snap ring keeps the rod from dropping down.