Fluid Flywheel - Description from BUT manual

(see pictures: section through A-type or L-type, exploded view of L-type, and part cut away.)

The fluid coupling fitted to both A- and L-type engines consists in each instance of two parts: the rear casing which is secured to the engine flywheel (which in turn is secured to the crankshaft); and the runner, which is free to rotate within the outer casing (formed by the flywheel and the rear casing) and is coupled by the joint flange of the freewheel unit.

The rear casing and the runner are each provided with a series of pockets seperated by radial-webs formed on their inner surfaces.

The runner shaft which is bolted to the runner is located in two bearings, one of which is fitted in the flywheel and the other in the rear casing. The flywheel or spigot bearing is located into the flywheel bore on the A- type engine, whereas on the L-type engine this bearing is carried in its own housing which in turn is setscrewed to the flywheel.

A self-adjusting bellows-type packless gland oil seal is fitted to the outer side of the rear casing.

General Maintenance
Check the oil level in the fluid coupling and top-up if required.
Check the runner shaft bellows gland for oil leaks.

Other Instructions
To drain and re-fill
To renew bellows oil gland
To remove and refit
To dismantle