1980/01/07 Caterpillar

Improved Pivot Pin Assemblies Now Used Between End Of Steering Cylinder And Gooseneck {4303,6209,7107}

Usage:

641B, 651B and 657B Tractor-Scrapers

Description of Change: Improved pivot pin assemblies are now used to fasten the steering cylinders to the gooseneck on 641B, 651B and 657B Tractor-Scrapers. Also, new steering cylinder assemblies are used.

These new pivot pin assemblies are of a full floating design. The new steering cylinder assembly uses two (2) sleeve bearings.

Seizure was some times possible with the former pin assemblies and cylinder assembly.

Adaptable To: The new parts, used together, are replacements for the former parts as shown in the chart. The new parts are adaptable to all earlier 641B, 651B and 657B Tractor-Scrapers.

If desired, the bores in the steering cylinders on earlier tractor-scrapers can be machines to a 3.498 ± .001" (88.85 ± .02 mm) diameter and two 3G9687 Sleeve Bearings installed.

See the Illustration.

Dimension for modification of steering cylinder for installation of bearings.

Caterpillar Information System:

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

1980/01/07 Different Steering Cylinder Hose Prevents Failures {4304}

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}

1990/01/08 New Tilt Cylinder Head Permits Bucket To Correctly Dump At Any Height{5104}

1990/01/08 Erratic Transmission Shifting On Machines Equipped With Individual Clutch Modulation (ICM) Transmission Controls{3167}

1990/01/08 Drag Brake And New Hand Control Used To Reduce Freespool Chattering In Winch{5163,5159}

1990/01/08 Bearings Available For Repair Of Bulldozer Push Arm Connectors{6060,6061}

1990/01/08 Be Sure To Use Correct Ripper Lift And Tilt Cylinders On Tractors With Increased Hydraulic Pressures{5352,5356}

1990/01/08 Seals Available To Service Impact Ripper Valve Assembly{5351,6317}

1990/01/08 Incorrect Wiring Of Start Switch To Starter Relay{1453,1408,1426}

1980/01/07 New 6V114 Gauge Assembly Available To Measure Brake Drum Wear {0653,4252}

1980/01/07 New Stronger Hub For Torque Converter Impeller Is Made Of Nodular Iron {3101}

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

1980/01/07 6V2091 Tap Available For Repairs On Spiralock Threads For Bevel Gear And Steering Clutch Case {0611,4059}

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

1980/01/21 Adjustable Spanner Wrench For Screw-On Pistons In Ripper Lift And Blade Tilt Cylinders{0614,5100,5350}

1980/01/21 Support Blocks Are Now Available For The Ends Of The Equalizer Bar{7206,7209}

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 Complete Tire Valve Group Must Be Ordered For Parts Replacement Of A Tire Valve Body{4202}

1980/01/21 New Hose Assemblies Used For Supply Lines To Elevator Motor{5057,5314}

1980/01/21 Longer Bolts And Spacers Now Used In Service Brake Groups{4256,4251}

1980/01/21 Drain Holes Added To Roof Panel And Channels On ROPS{7323}