Rolls-Royce 20/25 - starter motor clutch bits

 

 

motor shaft

 

The complete motor without its clutch assembly.  The splined on the shaft end have two short, double-width, splines to accommodate the dog plus one longer double-width spline for the nut that holds the friction disks.

pinion & cage

 

The forward-facing end of the clutch cage and the pinion that connects with the starter ring on the flywheel.

pinion back

 

Both of the previous components inverted.  The central bush on the pinion acts as a limiter for the hollow shaft.  The washer, shown uppermost here, is free to rotate and supports the large spring.

shaft

 

From the left: the shaft and return spring; threaded nut that carries the friction disks; end plate; dog nut.

The dog nut is left hand thread and locks the end plate against the machined ring on the right of the carrier nut.

cap and ring

 

The end cap for the clutch assembly and the lock ring that holds everything in place.

spring body

 

Two of the cage legs have been damaged.  The locking slot has completely snapped off one leg and is half-missing on another.  The cage has been in this condition for at least 20 years nd has caused no problem.  Internal spring pressure is relatively light and the circular lock ring will still keep everything in place.

The block at the bottom of the picture is inverted.  The brass pressure plate is spring loaded to avoid damage to the pinion.  The main internal spring locates against the flange.