Rolls-Royce Phantom III - adjusting the clutch


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R-R PIII - adjusting clutch levers

The clutch release bearing assembly is used as a datum for setting the clutch actuating arms.  The face of the trunnion must be set exactly 0.875" (7/8") from the face of the pressure plate case.  The levers are then adjusted, until they just touch the the trunnion face, by turning the lockable screws at the outer end of the lever housings.  I made a spacer (see below) to ensure an accurate and consistent gap.

I found that it took about an hour to get these levers set correctly because the adjusting screws moved slightly when the locknuts were tightened.  The air was getting blue as this operation is basically very simple.  I have performed this procedure before - in the car through the inspection cover - and completed it in about 15 minutes.

Anyway, after all is tightened up, when the trunnion is held lightly against the levers there should be no movement.  This can be judged best by trying to waggle the levers back and forth and listening for any slight clicking - if there is then start again!  Accuracy is important because the running clearance, with the clutch fully disengaged, is only 0.010".

R-R PIII - clutch adjusting spacer Close-up of the spacer in position.
R-R PIII - clutch spacer Made up from aluminium scrap.  The spacer (left) is exactly 0.875" long.
R-R PIII - threaded insert The rear face of the block has 4 blind, threaded, holes for attaching the upper clutch casing.  Steel inserts are screwed into these holes (R/H thread) to provide a stronger purchase for the bolts.  These inserts were full of debris and had to be cleared before assembly.
R-R PIII - flywheel timing marks Close-up of the flywheel markings - A1IO is the important one at the moment.  (Standing for cylinder #A1 Inlet valve Opens).  Note that this is positioned at 6 degrees AFTER TDC.
R-R PIII - timing markers

Upper half of the clutch casing temporarily installed to accurately locate the timing marker ('P').  The A1IO mark is shown at 'M'.

The tube 'T' is the out let from the one-shot system onto the clutch release bearing.

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