1985/04/01 Caterpillar

Improved Vibration Damper Guard Group Has Flexible Mounting

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

1985/04/01 New Turbocharger Oil Supply Tube Assembly Used

1985/04/01 Changes To Exhaust Manifolds Help Prevent Broken Studs

1985/04/01 Crankcase Explosion Relief Valve Kit Available

1985/04/01 Several Types Of Automatic Voltage Regulators (AVR) Used In SR4 Generators

1985/04/01 Check Cylinder Block And Head Flatness Whenever There Is A Head Gasket Failure

1985/03/01 Installation Of Heli-Coils In Holes With Damaged Threads

1985/03/01 New Air Cleaner Element Creates Less Restriction

1985/03/01 Cross Link Between Fuel Racks Has Smoother Surface

1985/03/01 Dowtherm 209 Full-Fill Coolant

1985/03/01 Input Shaft And Flange Available As An Assembly; Makes Alignment Easier

1985/03/01 New Transmission Control Valve And Pressure Relief Valve Are Used With High Flow Oil Pump

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

1985/04/01 Preferred Locations For Water Temperature Protection Devices

1985/04/01 New Main Shaft Bearing Assembly Has Reduced End Play

1985/04/01 Differential Oil Pressure Gauge For Oil Filter Shows High Differential Pressure

1985/04/01 New Outer Governor Spring And Torque Control Pin Used In Governor And Pump Groups

1985/04/01 Additional Zinc Rods Improve Service Life Of Sea Water Heat Exchanger

1985/04/01 Improved Oil Ring For Pistons Eliminates Expander Problems That Lead To Ring Breakage During Installation

1985/04/01 New Compression Washers (Gas Seals) Used On 7000 Series Fuel Injection Nozzles

1985/04/01 Changes To Fuel Systems{1250,1251,1252,1253,1254,1100}

1985/04/01 Specification Changed For Engine Oil Capacity

1985/04/01 Make Sure Air Cylinder For Governor Actuation Is Correctly Adjusted

1985/04/01 Electric Hour Meter Failures