1985/04/01 Caterpillar

Improved Vibration Damper Guard Group Has Flexible Mounting{1205,1200}

Usage:

3500 Series Industrial, Marine And Generator Set Engines

Description of Change: The damper guard group used on the above engines has been changed to include flexible mounting. Formerly, the guard assembly was mounted rigidly to the engine. At some engine speeds, resonant vibration of the guard could cause the guard to crack. The new flexible mounting will prevent the resonant vibration. See the illustration.

Adaptable As: The improved ¹1W4923 Guard Assembly is a direct replacement for the former 1W4923 Guard Assembly when the components of 8N9639 Damper Guard Group, shown in the chart, are added.

New components of the 8N9639 Damper Guard Group.

NOTE: Tighten the six 308535 Bolts and the four 3B1915 Bolts to a torque of 15 ± 3 N·m (11 ± 2 lb ft).

Caterpillar Information System:

1985/04/01 Use Of Fuel Injection Timing Information In The "Fuel Setting And Related Information" Microfiche{0600,0782,1250}

1985/03/25 New Main Shaft Bearing Assembly Has Reduced End Play{3306}

1985/03/25 Changes To Turbocharged Truck Engines For 1985{1000,1050,1052,1100,1200,1250,1252}

1985/03/18 Improved Oil Ring For Pistons Eliminates Expander Problems That Lead To Ring Breakage During Installation{1215}

1985/03/18 Remanufactured Bare Cylinder Heads (U.S. And Canada){1101,7754}

1985/03/18 New Service Manual Binders Are Made From Thicker Material{0375}

1985/03/18 Internal Seals In 7000 Series Fuel Injection Nozzles Cannot Be Replaced{1254}

1985/03/18 New Service Tools Available{0600}

1985/03/11 Input Shaft And Flange Available As An Assembly; Makes Alignment Easier{3303}

1985/03/11 Dowtherm 209 Full-Fill Coolant{1350}

1985/03/11 New Cooling System Temperature Regulator Available{1355}

1985/03/11 New Crankshaft Seal Groups Used On More 3400 Series Engines{1160,1161}

1985/04/01 New Compression Washers (Gas Seals) Used On 7000 Series Fuel Injection Nozzles{1254,1250}

1985/04/01 Information For Ordering kPa or Dual Scale Gauges{0600}

1985/04/01 Check Cylinder Block And Head Flatness Whenever There Is A Head Gasket Failure{1100,1200}

1985/04/01 New Lubricator Tip Available For Track Seal And Lubrication Testing Group{0600,0645}

1985/04/01 New Turbocharger Oil Supply Tube Assembly Used{1052,1307}

1985/04/01 More Tools Added To 6V9413 Custom Track Service Tool Kit{0600}

1985/04/08 Changes To Exhaust Manifolds Help Prevent Broken Studs{1059}

1985/04/08 Preferred Locations For Water Temperature Protection Devices{7403,7417,7420}

1985/04/08 Electric Hour Meter Failures{7450,7478}

1985/04/08 Differential Oil Pressure Gauge For Oil Filter Shows High Differential Pressure{1300,1306,1315}

1985/04/08 Several Types Of Automatic Voltage Regulators (AVR) Used In SR4 Generators{4450}

1985/04/08 Additional Zinc Rods Improve Service Life Of Sea Water Heat Exchanger{1379}