BUCKET AS 9EL2088 - Caterpillar

Introduction
This Special Instruction provides the necessary repair information to repair cracked tubes on D10N rear track roller frames. Use this instruction with the Service Manual for the removal, disassembly, assembly and installation procedures.Remove all major components of the roller frame including the idlers, major bogies, bogie pads and twister resistor. Clean the roller frame of any oil, both inside and outside of the assembly.Do not perform any procedure, outlined in this publication, or order any parts until you read and understand the information contained within.Reference: Service Manual, Parts Book and Undercarriage Reconditioning Guide SEBF8500Rear Track Roller Frame Welding Procedure
Before doing any service work which requires separating a track, a thorough inspection of the front track roller frame must be made. See Special Instruction SMHS8273-02. The tractor must be on a hard, level surface before the track roller frame is removed.
1. Remove the leaking roller frame from the machine.2. Disassemble the track roller frame.3. Remove the bogies, the bogie pads, and the twister resistor from the rear track roller frame.4. Drain the oil and clean the rear track roller frame thoroughly. 5. Position the roller frame with the belly plate up as shown above. 6. Identify leaking plug welds using a dye penetrant. The plug welds most likely to be cracked are those located directly under the bogie pads. However, all plug welds should be inspected.Also, check the roller frame tube inside diameter for cracks which have extended through the tube cross-section. 7. Use a soap stone to mark a 152.4 mm (6.0 in) wide section of the belly plate. The length of plate will vary depending on the number of cracked plug welds. 8. Remove the belly plate section and plug welds using the air carbon arc process or scarfing torch. Use caution when cutting the belly plate, not to damage the tube under the plate. 9. Grind the tube flush. Use a dye penetrant to locate any cracks. 10. Drill a 6.4 mm (.25 in) hole at the end of each crack to prevent further propagation. Follow with a 9.5 mm (.38 in) hole to a depth of 6.4 to 9.5 mm (.25 to .38 in). 11. Grind out all cracks. Sometimes a large, circular chunk may be removed as shown above.12. Periodically use a dye penetrant to check if all the cracks have been removed. 13. After all the cracks have been removed, recheck with a dye penetrant.Place a ceramic or copper back-up at the root of the removed crack to help contain the weld. The back-up can be held in place with a brace within the tube.14. Use a 2.4 or 3.2 mm (.09 or .12 in) diameter E7018 electrode or 1.1 mm (.045 in) diameter solid wire to build-up a bottom. Use stringer passes to keep heat input low. Do not over-weld with each pass because cracking will occur.15. Continue using stringer passes until a second layer has been built. Allow the weld area to cool to the touch between passes to prevent over-heating