New Air Compressor Crankshaft Has Improved Spline Lubrication
Usage:
3176 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 9Y9159 Air Compressors. The new crankshaft assembly is effective with 2YG8551.
New 4P2974 Crankshaft Assembly.
Caterpillar Information System:
1990/12/01 Improved Fuel Injection Pump Groups Have New Injector Groups
1990/12/01 Tools Available For Out-of-chassis Dynamometer Testing Of Electronic Engines
1990/12/01 Remanufactured Camshafts And Cam Kits Available For Parts Service
1990/12/01 New Rotor Used In Brakesaver Group; Regulator Valve Improved
1990/12/01 Personality Module Software Updated; Do Not Troubleshoot Diagnostic Code 55 (No Detected Faults)
1990/12/01 New Engine Magnetic Speed Sensor
1990/12/01 New Seals Available For Parts Service Of Noncurrent Water Lines Group
1990/12/01 New Bronze Thrust Plate Used On Center Main Bearing Of Crankshaft Groups
1990/11/01 New Bearing Kits Used In Turbocharger Cartridge Groups
1990/11/01 Correct Procedures For Starting, Stopping And Transporting A Product With A Turbocharged Engine
1990/11/01 Service Tips For Piston Cooling Jets (Tubes)
1990/11/01 Use Status Screen On Electronic Control Analyzer Programmer (ECAP) When Checking The Calibration Of The Timing And Rack Sensors; Correction To Systems Operation, Testing & Adjusting for 3406B (PEEC) Diesel Truck Engine, Form SENR3485-01
1990/12/01 New 7E5085 Bushing Replaces Former 2M4314 Bushing In Fuel Injection Pump
1990/12/01 Improved 9W1077 Start Switch Assembly And 7N4160 Heat Start Switch Group
1990/12/01 Correct Handling And Installation Of Temperature Switch Assemblies
1991/01/01 New 3E0020 Vehicle Speed Buffer Used
1991/01/01 Update Information For Exhaust Manifolds
1991/01/01 Checking Crankshaft Journal Surface Hardness On Remanufactured Crankshafts
1991/01/01 New Program Measures Customer Satisfaction
1991/01/01 List Of Service Publications
1991/01/01 Incorrect Specification For Tightening Turbocharger Compressor Nut In Service Manual For 3306B Diesel Truck Engine, SEBR0545-01
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}
1991/03/01 New Bracket Assemblies Used In Lifter Group{1209,1281}
1991/03/01 New 0R3231 Remanufactured 3208 Truck Engine Available{1000,7754}