Recently rebuilt my tranny and it works great except for the kickdown from 2nd to 1st It slips or dosent engage. This is the only gear that slips and it is only downshifting or kickdown 2nd to 1st. Also recently changed the 1-2 Acuumulator.

Could a loose clutchpack during rebuild cause this?

A kickdown cable, valve? Anything?

Help VERY much appreciated