Perkins 1104D NH1 Systems Operation Testing And Adjusting page 9

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Lower idler gear which turns the gear of the
lubricating oil pump.
Lip type seals are used on both the front of the
crankshaft and the rear of the crankshaft.
A timing ring is installed to the crankshaft. The timing
ring is used by the ECM in order to measure the
engine speed and the engine position.
Illustration 8
Gears and Timing Gear Case
Illustration 9
The crankshaft oil seal is mounted in the aluminum
timing case. The timing case cover is made from
pressed steel.
The timing gears are made of steel.
The crankshaft gear drives an upper idler gear and
a lower idler gear. The upper idler gear drives the
camshaft and the fuel injection pump. The lower idler
gear drives the oil pump. The water pump drive gear
is driven by the fuel injection pump gear.
The camshaft and the fuel injection pump rotate at
half the engine speed.
Camshaft
Illustration 10
The engine has a single camshaft. The camshaft
is made of cast iron. The camshaft lobes are chill
hardened.
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The camshaft is driven at the front end. As the
camshaft turns, the camshaft lobes move the valve
system components. The valve system components
move the cylinder valves.
The camshaft gear must be timed to the crankshaft
gear. The relationship between the lobes and the
camshaft gear causes the valves in each cylinder to
open at the correct time. The relationship between
the lobes and the camshaft gear also causes the
valves in each cylinder to close at the correct time.
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Systems Operation Section
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