The freewheel was between the fluid flywheel (which acted as an automatic clutch) and the gearbox. It was a protection device that prevented the engine being rotated fasted than designed such as when going downhill.
The components are: 1 - Yoke flange; 2 - Dowel; 3 - Roller; 4 - Splined Sleeve; 5 - Outer Cage; 6 - Driving Shaft; 7 - Sleeve. When the driving shaft is turned in the normal direction, the rollers lock the two halves together as seen in the close-up on the right, if the output side travels faster then the rollers dislodge and the two halves disconnect.
Left: the components of a dismantled freewheel.