RETAINER 8N7296 - Caterpillar

Ignition systems can cause electrical shocks. Avoid contacting the ignition system components and wiring during operation.
Maintenance of the spark plugs is required in order to achieve the following benefits:
Normal fuel consumption
Normal level of emissions
Maximum service life of the spark plugsThe service life of the spark plugs is affected by fouling due to deposits from the oil and by peak voltage. Maintenance of the ignition system is also affected by voltage. Higher voltage is required by higher inlet manifold air pressure and a higher compression ratio. Higher voltage reduces the service life of components such as spark plugs, wires, and transformers.Removing the Spark Plug
Pulling on the wiring harness may break the wires. Do not pull on the wiring harness.
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Remove cover (1) .
Pressurized air can cause personal injury. When pressurized air is used for cleaning, wear a protective face shield, protective clothing, and protective shoes.
Debris may have collected in the spark plug well. Thoroughly remove any debris. Use compressed air. The maximum air pressure for cleaning purposes must be below 207 kPa (30 psi). Ensure that the area around the spark plug is clean and free of dirt and debris.
To loosen the spark plug, use a 2P-5481 Deep Well Socket. After the spark plug has been loosened, remove the spark plug by hand in order to detect problems with the threads. After the spark plug has been removed, discard the used spark plug gasket.
Do not use a thread tap. A thread tap will remove metal unnecessarily. The threads could be stripped and the cylinder head could be damaged.
If the spark plug resists removal by hand, apply penetrating oil to the threads. Use the wrench and apply steady pressure to the spark plug until the spark plug is loose.If the spark plug can not be removed by hand, clean the threads with a 154-9521 Spark Plug Seat Cleaner. This tool scrapes debris from the seat and from the threads in the cylinder head.Inspecting the Spark Plug
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(1) Terminal post (2) Insulator (3) Shell (4) Gasket (5) ElectrodeTerminal post (1) must not move. If the terminal post can be moved by hand, carefully tighten the post into the threads of the insulator. If the post cannot be tightened, discard the spark plug.Inspect insulator (2) for cracks. If a crack is found, discard the spark plug.Faint marks may extend from shell (3) onto the insulator. The marks may be a result of corona that forms at the top of the shell. The conductor will develop a corona when a very high voltage ionizes the air. This is a normal condition. This is not an indication of leakage between the shell and the insulator.Inspect shell (3) for damage. Cracks can be caused by overtightening the spark plug. Overtightening can also loosen the shell. Discard any spark plug that has a shell that is cracked or loose.
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(6) Precious metal tips on the electrode and the ground strapCaterpillar spark plugs have precious metal tips (6) on the electrode and the ground strap. This material