GEAR ASSEM. 9S1179 - Caterpillar

Introduction
The eight major mechanical components of the basic engine are the following parts:
Cylinder block
Cylinder head
Pistons
Connecting rods
Crankshaft
Vibration damper
Timing gear case and gears
CamshaftCylinder Block
Illustration 1 g01907673
Typical example
The cast iron cylinder block for the C7.1 engine has six cylinders which are arranged in-line. The cylinder block is made of cast iron. The cylinder block provides support for the full length of the cylinder bores. The cylinder bores are machined into the block.The cylinders are honed to a specially controlled finish in order to ensure long life and low oil consumption.The cylinder block has seven main bearings which support the crankshaft. Thrust washers are installed on both sides of number 6 main bearing in order to control the end play of the crankshaft. The thrust washers can only be installed one way.Passages supply the lubrication for the crankshaft bearings. These passages are machined into the cylinder block.Cooling passages are cast into the cylinder block in order to allow the circulation of coolant.The cylinder block has a bush that is installed for the front camshaft journal. The other camshaft journals run directly in the cylinder block.The engine has a cooling jet that is installed in the cylinder block for each cylinder. The piston cooling jet sprays lubricating oil onto the inner surface of the piston in order to cool the piston.A Multi-Layered Steel (MLS) cylinder head gasket is used between the engine block and the cylinder head in order to seal combustion gases, water, and oil.Cylinder Head
Illustration 2 g03346701
Typical example
(1) Valve keepers
(2) Valve spring retainer
(3) Valve spring The engine has a cast iron cylinder head (5). The lower part of the inlet manifold (6) is integral within the cylinder head. There are two inlet valves and two exhaust valve for each cylinder. Each pair of valves (7) are connected by a valve bridge that is controlled by a pushrod valve system. The ports for the inlet valves are on the left side of the cylinder head. The ports for the exhaust valves are on the right side of the cylinder head. The valve stems move in valve guides that are integral in the cylinder head. There is a renewable stem seal (4) that fits over the top of the valve guide. The valve seats are replaceable.Pistons, Rings, and Connecting rods
Illustration 3 g02394336
Typical example
The pistons (9) have a Quiescent combustion chamber in the top of the piston in order to provide an efficient mix of fuel and air. The piston pin (8) is off-center in order to reduce the noise level. The position pin (8) is retained in the correct position by two circlips (3).The pistons have two compression rings (1) and an oil control ring (2). The groove for the top ring has a hard metal insert in order to reduce wear of the groove. The piston skirt has a coating of graphite in order to reduce the risk of seizure when the engine is new to reduce friction and improve fuel economy.The correct piston height is important in order to ensure that the piston does