1985/08/19 Caterpillar

Improvements Made To Spark Ignited Engines{1100,1104,1105,1207}

Usage:

3304 And 3306 Spark Ignited Engines

Description of Change: Reports indicate that the exhaust valves in some 3304 and 3306 Spark Ignited Engines can stick open during operation. This is caused by the build-up of dried, hardened oil in the valve guide. The improvements to the above engines include some new components in the cylinder head groups, valve mechanism groups, cylinder head fastener groups and the valve mechanism cover groups. The new components will help eliminate sticking exhaust valves.

Adaptable To: The new components in the 3304 Spark Ignited Engine are listed in Chart A. The new components are in effect with 3304 Spark Ignited Engines 37Y848, 37Y851, 37Y980, 37Y986, 37Y998, 37Y1000, 37Y1018 and up. The new components are adaptable back to 37Y506.

The new components in the 3306 Spark Ignited Engine are listed in Chart B. The new components are in effect with 3306 Spark Ignited Engines 7Y2041, 7Y2052, 7Y2058, 7Y2063 and up. The new components are adaptable back to 7Y291.

Illustration 1. Installation dimension for new 7W7489 Guide.

Illustration 2. Install the 7W7480 Dowel in the 7W7479 Bracket (Rear) to the dimension shown.

Caterpillar Information System:

1985/08/19 New Format For Some Special Instructions{0300}

1985/08/12 Thread Lock Now Used On Timing Advance Bolts{1272}

1985/08/12 The 8T3115 Portable Track Lubricator Can Be Used To Drain And Fill Track Link Joints{0645,4169,4170}

1985/08/12 Halogen Head And Flood Lamps Are Now Available{7309}

1985/08/12 Location Of 6V5135 Setscrews In Fuel Pump Group{1250}

1985/08/12 Eliminating Interference Between Governor Housing And Tachometer Drive{1264,7487}

1985/08/12 Tachometer Drive Is Now An Attachment{1166,1250,7450,7452,7487}

1985/08/05 Correct Operation Of Disconnect Switches{1411}

1985/08/05 Counterweight Improves Stability Of 8S9902 Jib Group (Track) Tool Cart{0632}

1985/08/05 Remanufactured Cylinder Head Group For NA Engines Must Not Be Installed On T Engines{1100,1108}

1985/08/05 Head Gasket Replacement Procedure{0350,1100}

1985/08/05 Stronger Push Rod Used{1208}

1985/08/19 New Address And Phone Number For Ordering Fabricated Tool (FT) Drawings{0600}

1985/08/19 New Camshaft Installation Tools Available{0600}

1985/08/26 Improved Front Gear Housing Assembly Used In Engine Front Housing Group{1151}

1985/08/26 Dual Element Air Cleaner Group Available{1054,1051}

1985/09/02 Repair Kits Available For Air Actuator Used In Governor Control Groups{1250}

1985/09/02 Adjusting Pneumatic Speed Control For Correct Operation{1264}

1985/09/02 New Engine Pressure Group Available{0600,0770,0781}

1985/09/02 New Precombustion Chamber Seal Available{1106,1100}

1985/09/02 Use Correct Valves When Rebuilding Engines{1105,1103}

1985/09/02 Check Fuel Injection Nozzles In Overheated Engines{1254}

1985/09/02 Steel Fuel Pump Lifter Used{1250,1251}

1985/09/02 Fumes Disposal Group Improved{1317}