2009/05/11 Caterpillar

Agricultural Tractor:

MTC755 (S/N: 8141-UP)

Excavator:

5130 (S/N: 5ZL1-UP)

5130B (S/N: 4CS1-UP)

5230 (S/N: 7LL1-UP)

5230B (S/N: 4HZ1-UP)

Off-Highway Truck:

776B (S/N: 6JC1-UP)

776C (S/N: 2TK1-UP)

776D (S/N: 5ER1-UP; AFS1-UP)

777 (S/N: 84A1-UP)

777B (S/N: 4YC1-UP)

777C (S/N: 4XJ1-UP)

777D (S/N: AGC1-UP; FKR1-UP; 3PR1-UP; AGY1-UP)

784B (S/N: 5RK1-UP)

784C (S/N: 2PZ1-UP)

785 (S/N: 8GB1-UP)

785B (S/N: 6HK1-UP)

785C (S/N: 1HW1-UP; APX1-UP; 5AZ1-UP)

789 (S/N: 9ZC1-UP)

789B (S/N: 7EK1-UP)

789C (S/N: 2BW1-UP)

793C (S/N: CBR1-UP; ATY1-UP)

793D (S/N: FDB1-UP)

797 (S/N: 5YW1-UP)

797B (S/N: JSM1-UP)

Track-Type Tractor:

D11N (S/N: 4HK1-UP; 74Z1-UP)

D11R (S/N: AAF1-UP; 8ZR1-UP; 9TR1-UP; 9XR1-UP; 7PZ1-UP)

Wheel Dozer:

854G (S/N: AMP1-UP; A4W1-UP; 1JW1-UP)

Wheel Loader:

992G (S/N: 7HR1-UP; AZX1-UP; ADZ1-UP)

994 (S/N: 9YF1-UP)

994D (S/N: 3TZ1-UP)

994F (S/N: 4421-UP)

994G (S/N: BEH1-UP)

994H (S/N: DWC1-UP)

Service Magazine SEPD1246, 28 February 2011, "A New Gasket Improves the Sealing between the Exhaust Manifold and the Cylinder Head on Some 3500 Machine Engines". The article has been revised in order to change the effectivity in the table below. The other information has not changed.

Description of Change: The new gasket is composed of multiple layers of steel. The gasket is resistant to degradation that allows the joint between the exhaust manifold and the cylinder head to loosen. Loosening of the joint can break the bolts that secure the exhaust manifold to the cylinder head.

Adaptable To: The new 320-8974 Exhaust Manifold Gasket replaces the old 7W-8145 Exhaust Manifold Gasket in the machines that are listed above.

Note: When you install the new 320-8974 Exhaust Manifold Gasket, also install new 5P-3875 Bolts and 5P-3961 Bolts. The original bolts may have been damaged by excessive vibration that is caused by loosened joints.

Table 1

Effectivity for the 320-8974 Exhaust Manifold Gasket
Sales Model	Serial Number
776D	S/N:AFS101
777D	S/N:AGC75003 S/N:DCB32224
785C	S/N:1HW135 S/N:APX01661
785C HA	S/N:5AZ428
789C	S/N:2BW1538
793C	S/N:4AR77003 S/N:ATY1125
793D	S/N:FDB1158
797	S/N:5YW278
797	S/N:JSM471
992G	S/N:ADZ6002 S/N:AZX840
994D	S/N:3TZ381
D11R	S/N:7PZ5020 S/N:9TR75005
D11R CD	S/N:9XR75002 S/N:AAF75004