Separation of the Ignition Transformer on G3500 Generator Sets and G3600 Engines{1550} Caterpillar

Engine:

G3516C (S/N: GSB1-UP; TJB1-UP; GZZ1-UP; RWA1-UP; DKR1-UP)

G3516E (S/N: GAS1-UP; SLY1-UP)

G3520C (S/N: MAD1-UP; GZJ1-UP; GZL1-UP; GZM1-UP; GZN1-UP; B9P1-UP; HAT1-UP; CWW1-UP; CWY1-UP; GDB1-UP; GHC1-UP; GHE1-UP; JBX1-UP; JBZ1-UP)

G3520E (S/N: GZG1-UP; GZH1-UP; HAL1-UP; SXY1-UP; GHM1-UP; GHR1-UP)

G3606 (S/N: 4ZS1-UP)

G3608 (S/N: BEN1-UP)

G3612 (S/N: BKE1-UP)

G3616 (S/N: BLB1-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

Illustration 1	g01364716
(1) Tilted top of the transformer

The transformers are being deformed due to high pressure in the spark plug well. An indication of high pressure is a popping sound when the transformer is removed.

The above condition can cause an internal tear in the potting material of the transformer. Many of the transformers continue to be operational. However, some transformers have failed. This problem can be identified by a tilted appearance of the top of the transformer. This tilt is a result of the internal tear. Refer to Illustration 1.

Improper maintenance is a root cause for the high-pressure buildup in the spark plug well. A leak path is created when the sealing surface is not properly cleaned. A leak path is created when a new seal is not installed with a spark plug. This leak path allows a pressure buildup of combustion gases in the spark plug well.

Poor maintenance of the spark plugs is a major contributor to damaged transformers. Damage due to poor maintenance is not warrantable.

Solution

Removing the Spark Plug

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Ignition systems can cause electrical shocks. Avoid contacting the ignition system components and wiring. Do not attempt to remove the valve covers when the engine is operating. The transformers are grounded to the valve covers. Personal injury or death may result and the ignition system will be damaged if the valve covers are removed during engine operation. The engine will not operate without the valve covers.

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Pressurized air can cause personal injury. When pressurized air is used for cleaning, wear a protective face shield, protective clothing, and protective shoes.

Follow this procedure when a spark plug is removed. Perform this procedure if a transformer with a tilted top is noticed.

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.

Use a 216-1685 deep well socket, an extension, and a breaker bar to loosen the spark plug. After the spark plug has been loosened, use the socket and extension to 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.

If the spark plug resists removal by hand, apply penetrating oil to the threads. To help the oil penetrate the threads, turn the spark plug back and forth until the spark plug is loose.

If the spark plug could not be removed by hand, clean the threads with a 9U-7511 Spark Plug Seat Cleaner . This tool scrapes debris from the seat and from the threads in the cylinder head. Be sure to clean any debris from the cylinder.

Installing the Spark Plug

Note: Do not use anti-seize compound on spark plugs. Most of the heat is transferred through the threads and the seat area of the spark plug. Contact of the metal surfaces must be maintained in order to provide the heat transfer that is required.

Ensure that the spark plug is clean and free of dirt and oil. Always use a new gasket when a spark plug is installed. If a used spark plug is installed, place a new gasket on the spark plug. Orient the tabs of the gasket toward the spark plugs electrode. Otherwise, the gasket may not seat properly. If a gasket for a spark plug is installed incorrectly, do not increase the torque on the spark plug in order to improve the seal. Do not reuse the gasket. Install a new gasket.

Install the spark plug by hand until the spark plug contacts the gasket. Torque the spark plug to the proper specification. Refer to the Specifications manual for the proper torque specification.