New Air Compressor Crankshaft Has Improved Spline Lubrication{1803}
Usage:
3306B Truck Engines
Description of Change: A new crankshaft is now being used for the air compressor. The new crankshaft has an orifice (1) to direct a jet of oil to the crankshaft drive splines. The former crankshaft relied on splash lubrication for the spline. The splash lubrication was insufficient, resulting in premature crankshaft spline wear. Spline wear causes excessive front gear train noise while the air compressor is building pressure.
Adaptable To: The new 4P2974 Crankshaft Assembly is a direct replacement for the former 7N7438 Crankshaft and is adaptable to earlier 1W7146 Air Compressors. The new 4P2975 Compressor Group is effective with 63Z20132.
New 4P2974 Crankshaft Assembly.
Caterpillar Information System:
1991/03/01 New Front Crankshaft Seal Used{1160,1202}
1991/03/01 New 0R3231 Remanufactured 3208 Truck Engine Available{1000,7754}
1991/03/01 New Bracket Assemblies Used In Lifter Group{1209,1281}
1991/03/01 Be Sure To Remove All Air From The Fuel System On A Truck That Has Run Out Of Fuel, Had The Fuel Filter Changed, Or Had The Governor Removed{1250,1256,1261,1264,1274}
1991/01/01 Incorrect Specification For Tightening Turbocharger Compressor Nut In Service Manual For 3306B Diesel Truck Engine, SEBR0545-01
1991/01/01 List Of Service Publications
1991/01/01 New Program Measures Customer Satisfaction
1991/01/01 Checking Crankshaft Journal Surface Hardness On Remanufactured Crankshafts
1991/01/01 Update Information For Exhaust Manifolds
1991/01/01 New 3E0020 Vehicle Speed Buffer Used
1990/12/01 Correct Handling And Installation Of Temperature Switch Assemblies
1990/12/01 Improved 9W1077 Start Switch Assembly And 7N4160 Heat Start Switch Group
1991/03/01 New Caterpillar Truck Engine Parts And Service Directory Available For U.S. & Canada{0375,0354,0370}
1991/03/01 1U5269 Mirror Tube Used With 1U5268 Borescope May Become Scratched{0777}
1991/03/01 List of Service Publications{0374,0375}
1991/04/01 Fuel Injection Pump Bushing Torque Increased
1991/04/01 New Diagnostic Code 28 "Check Throttle Sensor Adjustment " Is On 1991 Engines
1991/04/01 New Shaft Bracket And Oil Supply Plug Used In Rocker Valve Shaft Assembly
1991/04/01 Two Different Air Inlet Heater Control Modules Available
1991/04/01 Procedure For Applying 1U8846 Gasket Maker
1991/04/01 New Performance Category For Engine Crankcase Oil
1991/04/01 Correct Position Of Lockwashers For Electrical Components With Screw Terminals
1991/04/01 Simplified Battery Test Procedure SEHS7633-02 And Battery Test Sheet SEHS9326 Available
1991/05/01 Component Changes For 1991 Model 3176 (7LG, 43Z) Engines{1052,1087,1119,1215,1290,1292,1304,1361,1362,1378,1408,1901,1902,1912}