1999/09/06 Caterpillar

New Piston In Lift Cylinder Increases Clearance Between Tilt Lever And Axle Housing {5102,6116}

Usage:

938F (1KM, 2RM, 8SM, 7SN) Wheel Loaders

Description of Change: Interference, between the bucket tilt lever and axle housing, can occur on some 938F Wheel Loaders. Interference can happen when the bucket is racked back and completely lowered, while the lift cylinder is fully retracted.

The piston in the lift cylinder was replaced. The new piston has a shallower rod counterbore. The shallower counterbore increases the closed length of lift cylinder and prevents the tilt lever from contacting the axle housing.

Adaptable To: New 148-3669 Piston (1) replaced former 128-7673 Piston (3) effective with 128-7678 Lift Cylinder (Eng. Chg. 04), shown in View A of illustration.

NOTE: An engineering change number (Eng. Chg.) indicates effectivity of this improvement or adaptability to earlier cylinders. The cylinder part number, engineering change number, and date of manufacture are on the cylinder tag.

128-7678 Lift Cylinders (Eng. Chgs. 00-03), shown in View E of illustration, can be upgraded by adding one 7J6871 Washer (4), 6.0 mm (.24 in) thick, between the end of cylinder rod (2) and the bottom of the bore in former 128-7673 Piston (3).

128-7678 Lift Cylinder

(A) 128-7678 Lift Cylinder (Eng. Chg. 04)

(B) 1187.0 mm (46.73 in) Pin to Pin Dimension

(C) 10.0 mm (.39 in) Deep

(D) 15.0 mm (.59 in) Deep

(E) 128-7678 Lift Cylinder (Eng. Chgs. 00-04)

(1) New 148-3669 Piston

(2) Cylinder Rod

(3) Former 128-7673 Piston

(4) 7J6871 Washer

Caterpillar Information System:

1999/09/06 New Metering Pump Provides More Precise Steering Control {4312}

1999/09/06 New Hose Assembly For Air Suspension Seats Has Improved Service Life {7312,7324}

1999/09/06 New Governor Spring Has Improved Service Life {1265}

1999/09/06 New Wheel Improves Bearing And Wheel Service Life {4208,4006,4051}

1999/09/06 New Bracket Protects Flasher Control {1430}

1999/09/06 Front Gear Group Changed to Help Keep Oil Pump Adapter Assembly Bolts Tight {1206,1304}

1999/09/06 Improved Bearing For Torque Converter Drive Gear {3101,7551}

1999/09/06 New Transmission Oil Filter Used {3067,3068}

1999/09/06 Improvements To Air Cleaner Supports And New Software Help Prevent False Inlet Air Restriction Warnings {7452,1051,1071,1920}

1999/09/06 Improved Undercarriage Improves Service Life {4151}

1999/09/06 New Bulldozer Connectors Improve Service Life {6050,6061}

1999/08/30 Use 9U-6843 And 9U-6845 Reclaiming Stills To Recycle Coolant {0708,1352}

1999/09/06 A Special Instruction For Installing Bucket Control Linkage Assembly Modifications Is Available {6107,0374}

1999/09/06 Use 164-5848 Driver To Install Seals {6108}

1999/09/06 VIMS Version 9.6X Class Of On-board Software Available {7601}

1999/09/06 Modification Of Governor Control Groups Eliminates Governor Sticking {1264,1265}

1999/09/06 New Plate Deflects Rain Water {1417}

1999/09/06 Improved Transmission Flow Control Valve Prevents Unstable Oil Pressure {3064}

1999/09/13 Water Pump Elbow Modification {1361}

1999/09/13 Correction To Transmission And Grapple Electronic Control System, Systems Operation Testing And Adjusting, SENR6686-01 {0374,3168,4800}

1999/09/13 Correction To Power Train Systems Operation Module, RENR3044 {0374,3168,4800}

1999/09/13 Steering Cylinder Now Uses Improved Rod Seals {4303}

1999/09/13 Hood Liner Support Brackets Modified To Eliminate Interference With Air Conditioner Compressor Switch {7251}

1999/09/13 New Connector Protects Pilot Control Valve {5059}