1990/10/29 Caterpillar

Improved 7W7730 Cylinder Head Gasket Provides Better Sealing Capability{1124}

Usage:

3500 Family of Engines Except 3508 (1ZF ),
3512 (3YF ),
3516 (4XF ) High Horsepower Generator Set Engines

Reference: Service Magazine; November 23, 1987; Page 14; "Improvements To Prevent Oil Leakage At Cylinder Heads" for 3500 Family Of Engines.

Description of Change: The sealant bead on the cylinder head gasket has been improved to provide a better seal. The sealant bead on the improved version does not cross grooves in the spacer plate and the cylinder head. Previously, the sealant bead crossed grooves on both sides of the spacer plate and on one side of the cylinder head where it went around the push rod compartment. This could cause uneven loading in the gasket which could lead to leakage at the cylinder head gasket joint. See the illustrations for the new and former head gasket design.

Adaptable To: The improved 7W7730 Cylinder Head Gasket is a direct replacement for the former gasket. The part number has not changed.

NOTE: See the appropriate Service Manual for the correct bolt tightening sequence. Do NOT exceed the maximum recommended cylinder head bolt torque of 469 N·m (345 lb ft).

Illustration 1. Improved 7W7730 Cylinder Head Gasket.

Illustration 2. Former 7W7730 Cylinder Head Gasket.

Caterpillar Information System:

1990/10/29 New Cylinder Head Gasket And Higher Cylinder Head Bolt Torque{1124,1101}

1990/10/29 Modification Of 1U7791 Valve Seat Driver{0782,1103}

1990/10/29 New Bearing Kits Used In Turbocharger Cartridge Groups{1052,7551}

1990/10/29 Governor Control Motor Polarity May Require A Change{1265,1408,7556}

1990/10/29 New Temperature Regulators Prevent Engine Overheating{1355}

1990/10/29 New CE (Caterpillar Environmental) Family Of Metal-Shell Connectors Used{7553}

1990/10/22 New "On Engine" Adjustment Procedure For 3161 Woodward Governor {1264,0782}

1990/10/22 Increased Capacity Oil Sumps Require Additional Oil And Different Maintenance Interval {1302,1318,7524,7525}

1990/10/22 Front Trunnion Bolts May Come Loose {1153,1154}

1990/10/22 Improved 7C1757 Exhaust Manifold Group {1059}

1990/10/22 Setscrew And Nut Available For Fuel Setting And Injector Synchronization {1257}

1990/10/22 Correct Procedure To Check For Grounds On Woodward 9905 Series, 2301A Control; Correction For Service Manual Module; 2301A Electric Governors (Load Sharing) For Generator Set And Industrial Engines; Form SENR3585-01 {1289}

1990/11/05 New Composite Halogen Headlights And Floodlights Available{1429,1434}

1990/11/05 Obsolete Capacitor In VR1 Voltage Regulators{4467}

1990/11/05 New Exhaust Manifold Gasket And Locks Used In Exhaust Manifold Groups{1059}

1990/11/05 New Stronger Exhaust Valve Push Rod Used In Valve Mechanism Groups{1208}

1990/11/05 Some Components Of The 7E3580 Engine Adapter Group For Allison AT545, MT543D, And MT653DRD Transmissions Are Not Serviced By Caterpillar{3279,1013,3009}

1990/11/05 Service Manual SENR3479-04 Available For Troubleshooting Engine Test Procedures{1901,1900}

1990/11/05 New Crankshaft Seal Groups Used{1160,1161,1202}

1990/11/12 New 7X1400 Digital Diagnostic Tool (DDT) Group Available {0782,0785,1900}

1990/11/12 Adjustable Exhaust Bypass Group Used; Provides More Precise Ability To Set Exhaust Pressure {1057}

1990/11/12 New Alternator Drive Pulley Seal Used With New Drive Pulley; Poly-Vee Belt Can Be Installed {1425,1357}

1990/11/19 Diagnostic Connector Used To Determine Starter Problems; Starter Monitor Unit Can Be Fabricated{0710,1408,1416,1426,1467,1553}

1990/11/19 New Caterpillar Battery Warranty Statement, SELF5124{1401,7780}