felt before shutdown or if there is any noticeable wear on the vibrators. If sliding surfaces of slide blocks are
worn, rotate both blocks to new surface. Scribe an "X" or other mark on the worn slide block surfaces so they
are not reused. Check flyball rod for wear and for straightness and replace as required. Check ball bearings
in ball head motor and flyball arms and replace as required. Replace flyball rod bushings if worn or scored.
Cover vibrator balls with a light grease and reassemble. Do not fill vibrator cup with grease, as this can
dampen the vibration. Check operation of pressure type oilers if so equipped.
3. Governor Ball Head (Woodward. Strap Suspended Type)
Quarterly. Add dashpot oil to top of ball head motor to fill internal dashpot. Do not use lubricating oil.
Annual. Observe operation of ball head and check for any unusual vibration. If any abnormal vibration is
noted, disassemble ball head and check condition of thrust bearing, ball head shaft bearings, and ball head
motor bearings. Follow manufacturer's alignment and reassembly procedure.
Governor Ball Head (Pelton)
Annual. Observe ball head and ball head motor for any unusual vibration or noise. Replace ball head
motor bearings if any abnormal vibration or noise is noted. Follow manufacturers instructions for
disassembly and reassembly.
5. Electro-Hydraulic Transducer (Electronic or Digital Governors)
Annual. Adjust transducer pilot valve so that it is centered with zero voltage to the transducer. Check
operation for any stickiness or erratic movement.
6.Woodward Oil Motor Vibrator
Annual. Check that oil motor vibrator is providing a 0.006- to 0.007-inch oscillation of the main valve and
that motor is turning in the range of 400 to 600 rpm (7 to 10 Hz). Adjust the eccentric bushing in the pivot
lever to change the magnitude of oscillation. Adjust the oil flow regulator to change the motor speed.
7. Pilot Valve
Annual. Disassemble pilot valve and remove all rust spots and oil varnish with a fine grade emery cloth
(320 to 500) and crocus cloth. Any nicks or scratches should be removed by stoning with a very fine flat
stone. Care must be taken not to round or break the edges of the valve lands. If wear is excessive or the
plunger does not move freely in the bushing, replace with a new matched plunger-bushing set.
8. Main and Auxiliary Distributing Valves
Annual. Check that main valve plunger is free. Shut off oil supply to pilot and main valves and disconnect
the pressure supply to the pilot valve. With the oil pressure relieved, lift main valve plunger until it hits the
opening stop nuts and drop it so it hits closing stop nuts. If the plunger drops freely, it is acceptable; but if
there is any binding or if the plunger drops sluggishly, disassemble the valve to determine the problem.
Check operation of transfer valve and auxiliary valve.