1987/02/23 Caterpillar

Stronger Timing Gear Housing; Additional Stud Used At Top Of Housing{1151,1201}

Usage:

3408, 3412 Engines In All Applications

Description of Change: A stronger timing gear housing and an additional stud at the top of the housing are now used in all applications of 3408 and 3412 Engines. The stud is installed in the top front center of the cylinder block in place of the pipe plug formerly at this location. The stronger housing and the stud fasten the top of the housing tighter to the center of the vee in the block. This prevents gasket leaks and keeps the aluminum housing from fretting against the iron block.

Adaptable To: The stud can be added to all earlier 3408 and 3412 Engines. Referring to the illustration, drill and counterbore a hole in the top center of the timing gear housing for the added stud. The counterbore is for the nut.

Modification to timing gear housing for the additional stud, nut and washer.

Replace the 9F2247 Plug in the center of the block with a 7C7407 Stud. Install a 5M2894 Washer and 1D4717 Nut on the stud.

Caterpillar Information System:

1987/02/16 Grommets Added To Dampen Vibration{1307}

1987/02/16 Fuel Ratio Control Diaphragms On 3161 Governors{1278}

1987/02/16 Some 2P4005 Oil Filter Assemblies May Be Difficult To Install{1318}

1987/02/16 Change To Interval For Valve Lash Adjustment{1103,1105,1123}

1987/02/16 Check Bolt Tightness Before Replacing Gaskets To Stop Coolant Leakage{1393,1362}

1987/02/16 Incorrect Use Of Fuel Heaters Can Reduce Engine Power{1296}

1987/02/16 Guidebook For Caterpillar Inspection And Maintenance Program For Standby Generator Sets{0354,0370,0372}

1987/02/16 Polarity Connections And Use Of Service Meter Films When Service Meter Kits Are Installed{7480,7000}

1987/02/16 Self-Powered Hour Meters Available{7480,7450}

1987/02/16 12-Volt Starter Solenoid Available For 7T2265 And 7T2266 Starting Motors{1407}

1987/02/16 Resistors Used To Protect Electrical Wiring{1400}

1987/02/16 The Importance Of The Disconnect Switch In Regard To Fire Suppression Systems With Automatic Actuation{7401}

1987/02/23 Two Front Timing Gear Housings Available{1162,1150}

1987/02/23 Water Temperature Regulators Standardized{1355}

1987/03/02 Bolt-On Roller Groups Available For Competitive Hydraulic Excavators{4150}

1987/03/02 Tools Available To Install Plastic Tie Straps{0709,0738}

1987/03/02 Check For Plugged Orifices In Mechanical Pressure Gauges{7450}

1987/03/02 Water Separator Available{1263}

1987/03/02 New 8T5261 Bushing Installer And Remover Adapter Tool Available{0600}

1987/03/02 New Fan Drives Used{1358}

1987/03/09 Cylinder Head Water Directors No Longer Needed In Direct Injection Engines {1115}

1987/03/09 New Air Cleaner Mounting Brackets Used For Heavy-Duty Air Cleaner Groups {1051}

1987/03/09 Improved Injector Clamp Eliminates Interference With Bridge {1290}

1987/03/16 Modification To Prevent Starter From Remaining Engaged With Flywheel After Engine Starts{1400,1450}