There is a process I have found to work well if there is no satisfaction on the TA.
This works: I adjust a worn set of linkages so that the pedal releases the shifter when pushed down 1/2 the distance to the full pedal travel from the place where the main clutch begins to move the tractor. Set the master clutch freeplay, (1.25 inches from the platform measured at the point where the pedal arm touches the platform. Next, tape a wooden 12" ruler next to the clutch arm so it sticks out forward past the pedal about 6 inches. With clear space ahead of the tractor, put it in first direct, and let out the clutch slowly. as you begin to move note the location of the beginning of tractor movement on the ruler (the number doesn't matter, it only allows you to know where the clutch starts to move the tractor.)
Stop the tractor, and mark that spot on the ruler.
with it shut off, and looking at the ruler, note how far it is from that mark, to fully pushed pedal. Set the TA clutch so it releases at 1/2 that distance. this setting allows the pedal push to release both clutches when pushed (correctly) to its travel stop. and assures that the TA clutch is fully engaged before the master clutch begins to move the power into the gears. Jim