Clutch mechanism first version (picture taken from the parts catalog)

The clutch mechanism has been changed three times.

The first production version can be seen on the both pictures on the right and below. On the right the explosion drawing from the parts catalog, below the gearbox cover with the seat bearing of the clutch lever.
The both push rods (a little steel ball is separating them) were changed first with the engine no. 664 (we’re talking about engine numbers because the gearbox has no own number). The next change was with engine no. 2286. The push rods thrust bearing was located in the clutch thrust plate, which also was changed each time.
All these early clutch mechanisms had some problems, obviously caused in the thrust bearing.

On the left the gearbox cover with the casted seat bearing for the clutch lever, used up to an engine no. of 3497.
On the right the late version with the screw-on seat bearing, which was used from no. 3498 on.

Since engine no. 3498 the clutch mechanism was completely redesigned (see picture right above and cross section below on the left).
The gearbox cover got a screw-mounted flange carrying the seat bearing instead of the casted version.
So the seat bearing for the clutch lever was now an extra part. The reinforced thrust bearing went from the clutch thrust plate to the opposite side just into this new flange
The push rod is no longer two-devided but made from one piece and had a square on each end. Very important is the plate spring (7444 K 1) and the thrust washers behind the flywheel, because the axial clearance of the crankshaft is adjusted with them, see hint on the cross section drawing left (taken from the Technical Bulletin No. 41 from July 1954).

Cross section drawing taken from the Technical Bulletin No. 14 from July 1954)