OPERATOR AR 2089725 - Caterpillar

Illustration 2 g03842076
Bucket linkage assembly failure locations
This repair procedure applies to the failure mode as shown in Illustration 2. The crack initiated from the welds between the boss and the channel plate.
Perform the welding in 1G / 2G and 1F / 2F positions.
Clean the cracked or damaged area to ensure that the area is free from oil, paints, grease, rust, etc.
Conduct a Dye Penetrant (DP) to ascertain the extent of the weld defect and precisely to find out the edges of the crack. Note: All slag or foreign material must be removed from the crack before checking with Dye Penetrant.
Remove the cracked region by gouging / grinding and check with Dye Penetrant (DP) to ensure that the crack should be removed completely. Note: If gouging is performed, preheat the location before gouging.
Ensure that slag and other by products from the removal process do not cover up the defective weld before checking with dye-penetrant.
Ensure that the entire defective weld has been removed down to solid material by using dye penetrant.
Extend the weld metal removal beyond the defect or crack a minimum of 25 mm (0.98 inch) from both ends.
Keep the rework surface free from moisture and dust.
Defects must be removed to sound metal prior to welding. Taper the ends of the gouged area to provide a smooth transition to the base metal. Welding Instructions
Illustration 3 g03841991
Bucket linkage assembly failure locations
For crack locations, refer to Illustration 3.
Illustration 4 g03842306
Partial Depth Crack
Illustration 5 g03842320
Full Depth Crack
(D) 2-3 mm
All the base metal crack has to be reworked before carrying out the welding rework. Refer to Illustration 4 for a partial penetration base metal crack and Illustration 5 for a through thickness base metal crack.
Illustration 6 g03842035
Welding detail in the failure location as per print requirement
Illustration 7 g03842098
Welding schematic for metal crack rework
Illustration 8 g03842099
Welding schematic for toe crack rework
Apply a weld on rework location as per drawing requirements. Refer to Illustration 6.
If crack is a weld metal crack, refer to Illustration 7.
If crack is a weld toe crack, refer to Illustration 8.
Make sure that the weld start – stop should be eliminated at corner location. Weld start – stop needs to be merged smoothly and it should be free from any weld defects like crater and lack of sidewall fusion.
Use suitable grinding or finishing equipment to smooth the surface of the built up area to the original profile (matching with the adjacent area).
Check for visual weld defect inspection, if anything noticed, grind the defective location and reweld the defect location
Check to ensure that the reworked area is free from external defects and check with DP test for defect free welding.
Check that reworked area is free from external defects and check with DP test for defect free welding. Refer to "Quality/Inspection".
After all finished welds are completed, apply needle peening. Repaint welded and grinded areas. Note: The final capping weld must not exceed 2 mm ( 0.08 inch), with good wetting profiles on the toes of the weld.Quality/Inspection
The weld shall be free from cracks, porosity, undercut, and incomplete fusion. All weld