2008/08/18 Caterpillar

Generator Set:

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

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

Engine News SEBD9553, 18 August 2008, "An Improved Top Piston Ring Is Used". Disregard the original article. Effectivity has been added to the models that are listed above.

Description of Change: Excessive liner wear may lead to the following symptoms: increased oil consumption, blowby and loss of cylinder compression. Excessive liner wear may lead to detonation on a single cylinder. The detonation occurs due to the presence of oil during combustion. The new top piston ring is designed with improved characteristics for wear with the cylinder liner.

Adaptable To: The new 309-4046 Top Piston Ring uses an improved material for the face and offset geometry for the profile of the barrel face. Testing of the new ring determined that wear on the cylinder is reduced.

To determine the condition of the engine, keep a log that records the following conditions. This will also enable the service intervals for the cylinder pack to be predicted.

• Oil consumption

• Blowby

• Cylinder compression

Refer to the Operation and Maintenance Manual, SEBU7681, "G3500C and G3500E Generator Sets" which contains guidelines for inspection intervals and criteria for determining when overhaul is required.

The expected in-frame overhaul for the G3500E is 20,000 hours for the new 309-4046 Top Piston Ring .

This new top piston ring is effective with the serial numbers GAS00265-UP and GZH00134-UP.