1978/02/27 Caterpillar

Replacement Seals And Wear Sleeves Now Available As A Crankshaft Seal Kit{1202,1160,1161}

Usage:

3406 and 3408 Industrial, Marine and Truck Engines;
3412 Industrial and Marine Engines;
621B, 623B, 631D, 633D, 637D and 637D P.P. Tractors;
988B Loaders;
245 Excavators;
and 16G Motor Graders

Description of Change: The crankshaft seals and wear sleeves used in the crankshaft groups and rear gear groups for the above models are available as a kit. Formerly, the seal and wear sleeve were sent separately. Now, these parts are assembled before shipment. This prevents damage to the sealing surfaces during shipment, storage and installation. Also, the seal kit has all of the necessary lubrication needed for installation.

Adaptable To: The 7N1999 Crankshaft Seal Kit can be installed on all earlier models shown.

INSTALLATION: Use the tools and procedures shown in Special Instruction Form SMHS7100. It will not be necessary to assemble the seal and wear sleeve or put lubricant on the seal lip.

Caterpillar Information System:

1978/02/27 Fabricated Adapters Permit Horizontal Mounting Of Transmissions On 1P2420 Transmission Repair Stand{0640}

1978/02/27 New Seal Assembly With Longer Ferrule Prevents Damage To Ferrule During Cylinder Head Installation{1100,1101,1300}

1978/02/13 Complete Set Of Contact Points For Dial Indicators Is Now Available In One Group{0653}

1978/02/13 Replacement Seal Group For Water Pump Impeller Now Has All The Seal Parts Plus An Installation Tool{1361,0622}

1978/02/06 Probable Causes Of Low Fuel Delivery During Testing On Fuel Injection Test Benches{0650,1250}

1978/02/06 New Water Temperature Regulator Opens At 180°F (82°C){1350,1355,7304}

1978/02/06 Attachment Groups Put Corrosion Inhibitor Directly Into Cooling System{1350}

1978/02/06 Successful Engine Service-3208 Engine Booklet Is Available{1000}

1978/02/06 Smaller Quantity Of Oil Now Used In Engine Oil Pan; Prevents Contact Between Crankshaft And Oil{1318}

1978/01/30 Do Not Change Factory Fuel Or Speed Settings On Truck Engines Unless New Settings Are Certified Under Applicable EPA Regulations{0336,0337,1257}

1978/01/30 Stronger Front Support Assembly{1153}

1978/01/30 New Water Pump Cover Has A Baffle And Wall To Send Coolant Flow From Bypass Line Directly Into Water Pump{1361}

1978/02/27 Stronger Exhaust Manifold Gasket Now Used{1059}

1978/02/27 Improved Fuel Priming Pump Assembly Has Better Sealing Characteristics; Repair Kit Available For Knob{1258}

1978/02/27 Modification Of Oil Pan For Installation Of Oil Sump Heater{1302}

1978/02/27 New Tachometer Drive Adapter Assembly Prevents Failure Of The Seals For the Tachometer Drive Group And Transfer Pump{7462,1256}

1978/03/06 Stronger Piston And Connecting Rod Are Tapered In Area Of Piston Pin{1213,1214,1218}

1978/03/06 5P8558 Pressure Gauge Calibrating Group Checks Pressure Gauges{0650}

1978/03/06 Use Again Specifications For Valve Springs Are Changed{1108}

1978/03/06 New Starter Motors Have Solenoid On Top Of Starter{1407,1453}

1978/03/13 5P8687 Tee Test Tooling Group{0651,5050}

1978/03/13 When A 6N5906 Hour Meter Will Not Operate Correctly, Check The Electrical Supply Before A Replacement Hour Meter Is Installed{7480,1400}

1978/03/13 Soft Washers And Lockwashers Are Now Used With The Mounting Bolts For Air-Fuel Ratio Control{1278,1264}

1978/03/13 The Causes And Reduction Of White Exhaust Smoke During Cold Engine Starts; Maintenance Aids Available To Decrease This Problem{1250,1383,1050}