1990/02/05 Caterpillar

Check Differential Pinion Bearing Retainer Bolts Whenever Transmission Is Removed {3254,3269}

Usage:

768C, 772B, 776B Tractors;
769C, 773B, 777B, 785, 789 Trucks

The bolts (shown in the illustration) that hold the differential pinion bearing retainer may come loose. In some cases, the bolts back out far enough damage to the pinion bearing seal. A damaged seal can allow oil to transfer from the transmission to the differential.

Always check the pinion bearing retainer bolts whenever the transmission has been removed for repairs. Replace the standard bolts (except for the 768C and 769C) with the ones listed below (these bolts have a thread locking patch). Tighten the bolts to 135 ± 14 N·m (100 ± 10 lb ft) on all models.

768C, 769C: Same bolt part number. Increase the bolt torque to 135 ± 14 N·m (100 ± 10 lb ft).

772B, 773B: 5K7143 Bolt (10 required)

776B, 777B: 5K7143 Bolt (12 required)

785: 310223 Bolt (12 required)

789: 310223 Bolt (16 required)

Location of bolts in typical differential group.

Caterpillar Information System:

1990/02/05 Steel Wear Strips Can Be Modified To Make Them Adjustable {6151}

1990/02/05 New Wider Mobil-trac System (MTS) Belt Available {4198}

1990/02/05 New Bevel And Transfer Gear Groups With Higher Capacity Bearing Used In Transmission Arrangements {3257,3256}

1990/02/05 Installation Procedure For Asbestos-Free Brake Linings {4110}

1990/01/29 New Seal Used In Governor Fastener Group{1264}

1990/01/29 Special Application Rotor Blade Tool Available{6821}

1990/01/29 New Rotor Arrangement Using Quick Change Tool System Is Available{6636}

1990/01/29 New Smooth Endless Conveyor Belt Used{6621}

1990/01/29 Improved Hub And New Bolt Used In Hydraulic Pump Coupling Group{5062}

1990/01/29 New Torque Converter Assembly Used In Transmission Arrangement{3101}

1990/01/29 Procedure To Modify Single Piece Suspension Support To Accept Bolt-on Spindles{7216}

1990/01/22 New Transmission Input Shaft Is Easier To Assemble{3189}

1990/02/05 New Hardware Improves Hydraulic And Transmission Tank Group {5056,3177}

1990/02/05 New Hose Clamps Have Constant Torque {5057,7554}

1990/02/05 Serviceable Parts Now Available For Cutter Clutch {5606}

1990/02/12 Seals Can Be Added To Suspension Cylinder Bearings{7213}

1990/02/12 Invert A-Frame Mounting Bolts To Obtain Correct Torque{3268,7200}

1990/02/12 Move The Grease Fitting To Improve Lubricant Penetration To Suspension Frame Bearings

1990/02/12 New Pressure Switch Used In Suspension Inhibit Circuit{7200}

1990/02/12 Heavy-Duty Wiper Motor Used{7305}

1990/02/12 New Mounting Bracket Improves Operation Of Hoist Cable{5136}

1990/02/12 Improved 2U0259 Rubber Cover For Hoist Valves Is More Resistant To Heat And Contaminants{5136}

1990/02/12 Use Correct Method When Installing Center Bonded Mounts{1273,5056}

1990/02/12 Longer Nipple Prevents Mud From Covering Rear Axle Housing Breather{3260}