Stop in for a cup of coffee

dukeboy_318 said
Is it possible you’re not getting the TQ converter seated fully?

With that transmission, I assume your thinking low pump pressure?
Does that also have a rear pump? and does that given driven by the tailshaft only?

WV64Signet said
@lkopaska

Twice now with this pushbutton A904 I can't get it to upshift. Fluid levels are correct.

Thoughts

Throttle 'kickdown' Shift linkage ?
That and the governer determine how the valves move.
Lemme look in a 66 book.