- Mini Hydraulic Excavator:
- 303C (S/N: BXT1-3801)
- 303.5C (S/N: DMY1-2732)
- 304C (S/N: FPK1-5328)
- 305C (S/N: HWJ1-3210)
- 303.5C (S/N: DMY1-2732)
Introduction
This Special Instruction describes the procedure to repair cracks in the front, left side cab post. Cracks can occur at the mounting locations of the grab handle. The location of possible cracks is shown in Illustration 1. Typical cracks are shown in Illustration 2.
Illustration 1 | g01622125 |
Location of the upper mounting of the grab handle |
Illustration 2 | g01622126 |
Typical cracks |
To perform this repair, all cracks are welded and two plates are added to the cab post. The plates must be welded to the cab post at the locations of the existing mounting holes for the grab handle. The plates must be fabricated locally.
This repair does not adversely affect the structural strength of the cab.
Machines that are equipped with a canopy are not affected.
Repair Procedure
- Use the dimensions in Illustration 3 to fabricate plate (1). Use 3.2 mm (0.126 inch) thick mild steel plate with a minimum yield strength of 140 MPa (20300 psi).
Illustration 3 | g01622509 |
Dimensions for plate (1) |
- Use the dimensions in Illustration 4 and in Illustration 5 to fabricate plate (2). Use 3.2 mm (0.126 inch) thick mild steel plate with a minimum yield strength of 140 MPa (20300 psi).
Illustration 4 | g01622901 |
Dimensions of plate (2) before the bend |
Illustration 5 | g01623261 |
Dimensions of plate (2) after the bend |
- Remove the existing mirror (if equipped) and the grab handle. Inspect the area around the weld nuts for cracks.
- Remove the paint from the repair site.
- Use a grinder to gouge out any cracks. Do not grind the full depth of the crack. Some material must remain in order to perform the weld.
- Weld the repair site. Grind the weld beads flush with the existing surface.
- Position plate (1) so that the hole in the plate is centered with the hole for the weld nut. Weld plate (1) into position. Provide a 3 mm (0.12 inch) weld completely around the plate.
Illustration 6 | g01623394 |
- Position plate (2) so that the hole in the plate is centered with the hole for the weld nut. Weld plate (2) into position. Provide a 3 mm (0.12 inch) weld completely around the plate.
Illustration 7 | g01623395 |
- Allow the welds to cool. Remove the weld splatter.
- Repaint the repaired area.
- Install the grab handle and the mirror (if equipped) on the machine.
When you install the bolt for the mirror, apply 9S-3263 Thread Lock Compound to the threads of the bolt and tighten the bolt to 55 ± 10 N·m (41 ± 7 lb ft).