1980/01/21 Caterpillar

Extended Shafts Now Available For Front Power Takeoff Units{3055}

Usage:

3408 Marine Engines

Description of Change: Extended shafts are now available for front power takeoff units that do not use a pilot bearing. The new shafts are six inches (152.4 mm) longer than the standard shafts, and are for use with an "outboard" bearing gives longer clutch service life, and the new shafts will make this type of installation easier. Formerly, it was necessary to fabricate a shaft to use with an outboard bearing. The pilot end is on the new shaft to permit bearing alignment during installation. After alignment of the power takeoff unit, remove the pilot bearing.

Adaptable To: All earlier engines. The new 5N7149 Clutch Shaft can be used in place of the 5N1780 Clutch Shaft for single-plate clutches (Twin Disc Model SP111). The new 5N7150 Clutch Shaft can be used in place of the 5N1781 Clutch Shaft for double-plate clutches (Twin Disc Model SP211). A Special Instruction, Form SMHS7684, is available with information to fabricate a bearing support and for alignment of the bearing and shaft.

Caterpillar Information System:

1980/01/21 Cooling System Improvements Prevent Expansion Tank Leakage{1354,1380,1153}

1980/01/21 New Piston Groups Have The Piston Pin Bore Off-Center, Away From The Thrust Side Of The Piston{1214}

1980/01/21 A Spring With A Lower Rate Is Now Used In The Fuel Filter Group To Give Less Fuel Pressure{1261}

1980/01/14 New Raw Water Engine Oil Cooler Is Used{1378}

1980/01/14 Use The FT1481 Bracket To Hold The 1P2371 Micrometer In Position During Bore Size Measurement{0655,0663}

1980/01/07 Improved Ring Seal Used At Rear Of Crankshaft {1161}

1980/01/07 8N1831 Fuel Nozzle Assembly Now Approved For Use In 1693 Truck Engine; Chart For Applications Of 8N1831 And 7N5005 Fuel Nozzle Assemblies {1254}

1980/01/07 Important: XT3 And XT5 Hose Assemblies Must Be Fabricated And Installed Correctly For Maximum Service Life {5057}

1980/01/07 New Exhaust Valve For Special Engine Applications {1104,1105}

1980/01/07 Fuel Heaters Are Now Available For Field Installation {1296}

1980/01/07 Do Not Use 5B1161 Wire To Check Main Bearing And Connecting Rod Bearing Clearances; Use Plastigage {0653,1203,1219,1230}

1980/01/07 Three New Pressure Gauges Are Now Available {0651}

1980/01/21 New Fuel Injection Nozzle Assembly Used{1254}

1980/01/28 New 6V199 Socket For Use On Fasteners In Areas With Limited Clearance{0612}

1980/01/28 Installation Procedures For 5N5880 Remote Shut-Off Group And 5N6336 Oil Pressure Indicator Gauge Group{7418,7403,7455}

1980/01/28 New Attachment Air Compressor Group and Lines Groups Have Improved Design{1065}

1980/01/28 Oil Drain Hole Added To Spacer Plate Cylinder Block To Permit Use Of Scroll Fuel System{1201,1221}

1980/02/04 New Cylinder Liner Has Improved Design To Keep Liner Temperatures Lower{1216}

1980/02/04 Change To Gear On Accessory Drive Shaft Assembly Gives Longer Service Life{1207,1206}

1980/02/04 Real Value Available Through Caterpillar Remanufacturing Programs{0374}

1980/02/11 Warning: Avoid Use Of Fuel Mixtures Of High Volatility. If You Are Exposed To Such Mixtures, Be Aware Of The Hazards Involved And Take Proper Precautions{1280}

1980/02/11 Use The Correct Water Temperature Contactor{1350,1100}

1980/02/25 How To Check Operation Of Hydramechanical Shutoffs On D379B, D398B, D399 Engines{7418}

1980/02/25 Revision Of Special Instruction Form No. SMHS7267, "Use Of 5P8709 Tool Group For Alignment Of Piston Cooling Jets" Has Important Changes{1307}