Hello,
Once again I have this issue for like 3 years. Trans would not shift from 2nd to 3rd on slow speed by default, it would go into neutral and after I give some more throttle it would downshift to 2nd. If I get to 40 mph or similar, once I release throttle pedal it would shift to 3rd and after that everything works fine - no problem at any speed. So my guesses are that something is stuck in valve body or governor.
Until now filter has been replaced, fluid flushed (was red even before flush), TV cable adjusted, bands adjusted.
The reasons why I suspect on governor valve is that th