1999/09/01 Caterpillar

Front Gear Group Changed To Help Keep Oil Pump Adapter Assembly Bolts Tight{1206,1304}

Usage:

All 3500, 3500 with EUI, 3500B and G3500 Commercial Engines

Description of Change: The front gear group used on these engines has been changed to help insure that the bolts that fasten the oil pump adapter assembly to the accessory drive housing remain tight. The new bolts that fasten the oil pump adapter to the accessory drive housing are one inch longer. These new longer bolts are used with spacers and washers. The new components allow increased bolt stretch, which will result in, improved bolt clamp load retention. This will help keep the new bolts tight.

Illustration 1.
Identification of new components in the 8N-7174 Front Gear Group.

7N-5263 Oil Pump Adapter Assembly (A).

0S-1590 Bolt (1).

5M-2894 Washer (2).

7C-8246 Spacer (3).

Adaptable To: Five new 0S-1590 Bolts (1), five new 5M-2894 Washers (2), and five new 7C-8246 Spacers (3) replace the five former 0S-1594 Bolts in the 8N-7174 Front Gear Group. This change is adaptable to all 3500 and G3500 Commercial Engines.

NOTE: If the areas where the new 7C-8246 Spacers contact the 7N-5263 Oil Pump Adapter Assembly are not level, spot face those areas on the pump adapter assembly. See Illustration 2.

Illustration 2.
Areas that may need to be spot faced on 7N-5263 Oil Pump Adapter Assembly.

Caterpillar Information System:

1999/09/01 New Rear Gear Group Available For Use In Landfill Applications{1206}

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1999/09/01 Wider Crankshaft Gear Used{1204}

1999/09/01 Engine Control For Dynamometer Or Diagnostic Testing{1000}

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1999/08/01 New Governor Control (Load Share Module) For Generator Set Engines{7490}

1999/08/01 Several New Service Manuals and Revised Service Manual Modules Available{0374,1000}

1999/08/01 Troubleshooting Hard Starting{1250}

1999/08/01 Cold Start Advance Solenoid Available{1272,1250}

1999/09/01 Improved Woodward EG3P Actuator Assembly Is Available{1264,1265,1716}

1999/09/01 Service Repair Kits Available For Deltec® Gas Pressure Regulators{1270}

1999/09/01 Summary Of Improvements To Deep Sump Oil Pans{1302}

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1999/09/01 New Connecting Rod Bolt Tightening Procedure{1218}

1999/09/01 New Water Temperature Regulators Used In Temperature Regulator Groups{1355}

1999/09/01 New Seal Kits Available For Servicing Heat Exchangers{1379}

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1999/10/01 New Water Pump Group (Basic) Includes Many Improvements {1361}

1999/10/01 Be Sure To Use The Correct Piston Cooling Jet Tube Assembly With Gallery Cooled Pistons {1331}

1999/10/01 Revised Maintenance Schedules For 3500 Diesel Commercial Engines {0374,1000}