GEAR (18 TEETH) 4K5781 - Caterpillar

Engine Description
Note: When you are ordering new parts, refer to the engine identification number in order to receive the correct parts.The C1.5 and C2.2 engines are diesel engines that are controlled with a mechanically actuated fuel injection pump. The engine cylinders are arranged in-line.Note: The C2.2 engines can be naturally aspirated and turbochargedThe cylinder head assembly has one inlet valve and one exhaust valve for each cylinder. Each cylinder valve has a single valve spring. The pistons have two compression rings and an oil control ring.It is important to ensure the correct piston height so that the piston does not contact the cylinder head. The correct piston height also ensures the efficient combustion of fuel which is necessary in order to conform to requirements for emissions.The crankshaft for the C1.5 engines have four main bearing journals. The crankshafts for the C2.2 engines have five main bearing journals. End play for all the engines is controlled by the thrust washers that are located on the rear main bearing. The C1.5 engines have aluminum bearing caps on the rear main bearing that act as thrust washers.The timing gears are stamped with timing marks in order to ensure the correct alignment of the gears during assembly. When the No. 1 piston is at top center compression stroke, the teeth that are stamped on the crankshaft gear and the camshaft gear will be in alignment with the idler gear.The crankshaft gear turns the idler gear which then turns the camshaft gear.The fuel injection pump and the fuel priming pump are mounted on the cylinder block. Both pumps are operated by the camshaft lobes.The fuel injection pump conforms to requirements for emissions. Adjustments to the fuel injection pump timing and high idle should only be made by trained personnel. The fuel injection pumps have mechanical governors that control the engine rpm.The engine oil pump is a gerotor type pump. The engine oil pump is located in the center of the idler gear. The engine oil pump sends lubricating oil to the main oil gallery through an oil relief valve that is located on the right side of the cylinder block. The rocker arm levers receive pressurized oil through an externally located oil line. The oil line runs from the main oil gallery to the cylinder head.Coolant from the bottom of the radiator passes through the belt driven centrifugal water pump. The coolant is cooled by the radiator and the temperature is regulated by a water temperature regulator.Engine Model Views
The following model views show typical features of the C1.5 and C2.2 engines. Due to individual applications, your engine may appear different from the illustrations.C1.5
Illustration 1 g03246538
Typical example
C2.2
Illustration 2 g03246558
Typical example
C2.2T
Illustration 3 g03246676
Typical example
(1) Top oil filler
(2) Fan
(3) Side oil filler
(4) Cylinder block drain plug
(5) Oil gauge (Dipstick)
(6) Rear oil drain plug
(7) Oil filter
(8) Electric fuel pump
(9) Secondary fuel filter
Illustration 4 g03246563
Typical example
(10) Air intake
(11) Turbocharger
(12) Aftertreatment system
(13) Flywheel
(14) Flywheel housing
(15) Starting motor
(16) Solenoid for starting motor
(17) Front oil drain plug
(18) NOx reduction system cooler
(19) Coolant outlet
Illustration 5 g03249056
Typical example
(20)