1992/10/05 Caterpillar

New Cylinder Head Groups Provides Lower Valve Guide Temperatures{1100,1104,1112,1123}

Usage:

G3306 (07Y) Engines

Description of Change: New cylinder head groups are used that improves the cooling around the exhaust valve guides. The improved cooling has resulted in a change to a shorter valve guide with a shallower counterbore in the guide inside diameter. The shorter valve guides have allowed the use of shorter valves and valve mechanism. This eliminated the need for risers under the valve springs and a taller valve cover. The improved cooling will reduce the chances of the exhaust valve sticking in the valve guides.

Adaptable To: The new 9Y3640 Cylinder Head Group and 7E1556 Valve Mechanism Group are in effect with G3306 TA Engine 07Y4100. The new 7E1285 Cylinder Head Group and 7E1556 Valve Mechanism Group are in effect with G3306 NA Engine 07Y4126. The service replacement cylinder head group used with these engines is the 6I2401 Cylinder Head Group.

A new service replacement 6I2402 Cylinder Head Group is available to provide improved valve guide cooling to earlier engines (before the above serial numbers). The new service replacement 6I2402 Cylinder Head Group must be used with the longer or taller valves and valve mechanism (the 7W7494 Valve Mechanism Group).

Caterpillar Information System:

1992/10/05 Thicker Head Gaskets Available For Use With Resurfaced Cylinder Blocks{1124}

1992/09/28 New NEXG4516 Marine/Industrial Service Program Module(SPM) Available {1900,0782}

1992/09/28 Service Tools Available {0600,0700}

1992/09/28 New Self Locking Bolt Used On Engine Side Covers {1201}

1992/09/21 New Fuel Injection Pump Groups Have Larger Diameter Camshaft Bores, New Lifter Assembly, And Shorter Plunger And Barrel Assembly{1251,1253,1281,1292}

1992/09/21 New Plug And O-Ring Can Help Prevent Oil Leakage At The Flywheel Housing Gasket{1157,1307}

1992/09/21 Replacement Mechanical Temperature And Pressure Gauges (Indicators) Retained By Push-On Metal Retainers{7450}

1992/09/07 Major Engine Component Changes{1201,1202,1205,1218,1219,1230,1253,1288,1331}

1992/09/07 Governor Specifications Are Available Through The Technical Information System{1264,0374}

1992/08/31 Supplemental Coolant Additive Requirements{1352,1395,1063}

1992/08/31 Connecting Rod Bearing Eliminates The Need For Mid-Life Connecting Rod Bearing Roll-In{1219,1202}

1992/08/31 Be Sure The Fuel Injection Pump Housing Is Compatible With 0R0715 And 0R2545 Remanufactured Short Blocks{1201,1253}

1992/10/05 Product Support Literature{0374}

1992/10/12 Improved Hour Meters (Electric){7450,7480}

1992/10/26 Improved Windshield Wiper Motor Crank Assemblies Available For Parts Service{7305}

1992/10/26 3406 Truck Engine Component Update{1052,1119,1201,1202,1205,1214,1218,1254,1288,1803}

1992/11/09 Correct Identification Of Rocker Arm Assembly Components{1123}

1992/11/09 Relay Replacement Kits Available To Replace Relays In Engine Mounted Junction Box{1423,1422}

1992/11/09 Replacement Governors For Early Engines{1264}

1992/11/09 Improved Fuel Injection Line Assemblies And Clamps Used{1252}

1992/11/09 Oil Holes In Crankshaft Main And Rod Journals{1202}

1992/11/09 New Liner Seat Inserts Available{1217}

1992/11/09 New 690 Main Rotor Lamination For 3500 SR4 Power Generators{4457}

1992/11/16 New Connecting Rod Assembly Used{1218}