2010/07/21 Caterpillar

Off-Highway Truck/Tractor:

777F (S/N: JRP1-UP; JXP1-UP)

Track-Type Tractor:

D11T (S/N: GEB1-UP; TPB1-UP)

Wheel Dozer:

854K (S/N: 2211-UP)

Wheel Loader:

992K (S/N: H4C1-UP)

993K (S/N: LWA1-UP; Z9K1-UP)

Service Magazine SEPD1152, 19 July 2010, "A New Piston, Piston Ring, and Oil Jet Tube Are Used on Certain C32 Machine Engines". Disregard this article. Refer to the article that follows.

Description of Change: A new piston, a piston ring, and a tube assembly are being introduced. The new piston eliminates contact between the land for the second piston ring and the liner.

The new piston ring has been designed with a wider gap to reduce possible carbon buildup.

The new oil jet tube is designed to work with the new piston. This new design will eliminate any possible contact between the piston and the tube.

Note: The new oil jet tube will work with the previous pistons.

Adaptable To: The new 20R-0193 Cylinder Pack Gp which contains the 357-5029 Piston Body As, 250-2940 Pin Retainer, and the 344-5153 Piston Ring are adaptable back to first production on the serial numbers that are listed above. Also, the new 355-6043 Tube As is adaptable back to first production on the serial numbers that are listed above.

Note: Due to the difference in weight of the new pistons and the existing pistons, the new piston must not be matched with the existing pistons.This change if effective for the serial numbers listed in Table 1.

Table 1

Effective Serial Numbers

S/N:221354-UP

S/N:H4C432-UP

S/N:Z9K371-UP

S/N:JRP2337-UP

S/N:GEB642-UP

S/N:TPB184-UP