A-904 Shifting from 1st to REVERSE!

doc540 said
The only clue I can think of is it only started doing the first to reverse shift after we'd adjusted the kick down linkage.

I test drove it for a couple of miles, kicking it from 2nd to 1st and 3rd to 2nd a few time.

Brought it back to the shop and talked with the owner a few minutes.

Got in it to drive to home and BAM! 1st to Reverse.

Did it twice, so I drove back to the shop in 1st.

I just don't see the kickdown adjustment doing that or anything remotely close to it.
All it does is raise and lower the pressures, and this HAS to be a mechanical failure of some sort in my mind.
Something broke, or something cracked and is leaking fluid by, or both.