SWITCH AS-PRESSURE 9X9643 - Caterpillar

TECHNICAL INFORMATION BULLETIN OCTOBER 29, 2003
BACKHOE LOADERS THIS TECHNICAL INFORMATION BULLETIN REPLACES THE OCTOBER 17, 2001 TIB, "BOOM REINFORCEMENT PLATES", COMPONENT CODE 6501. DESTROY THE OCTOBER 17, 2001 TIB.
416B (8ZK, 8SG)
416C (4ZN, 5YN, 1WR, 1XR)
416D (BFP, BGJ, BKG)
420D (FDP, BLN, BKC, BMC, BGD)
424D (BGP, BKR)
426B (6KL, 5YJ)
426C (7WN, 1ER, 1ZR, 6XN, 1CR, 1MR, 1NR, 1YR)
428B (7EJ)
428C (2CR, 8RN)
428D (BLL, BMT, BNB, BNS)
430D (BNK, BML)
432D (BLD)
436B (7FL, 6MJ)
436C (9JN, 1GR, 2BR, 1PR, 1RR, 8TN, 1FR, 2AR)
438B (3KK)
438C (9KN, 2DR, 1JR, 1TR)
438D (BPE, BPN)
442D (BRY, BRG)
Component Code(s) 6501SUBJECT: Boom Reinforcement Plates
PROBLEM:
In some severe applications the booms may crack in the nose area.
Illustration 1. Nose of Boom
A. 6 mm (.24 in) fillet (2 edges)
Crack
Line up edge against the current fillet weld and weld in with a 6 mm (.24 in) v-groove (2 edges).
SOLUTION:
Inspect the nose of the boom. Check both the side and the bottom. Add reinforcing plates to fix the cracks. A bottom plate needs to be added only if the crack has occurred on the bottom of the boom.
Side Plate Repair
1. Grind out and weld repair.
2. Drill 6.35 mm (1/4") hole at the crack termination.
3. Weld in new plates on both sides.
4. Blend in all welds smoothly to the existing welds.
Side Plate Rework
1. Weld in new plates on both sides.
2. Blend in all welds smoothly to the existing welds.
Illustration 2. Side Reinforcing Plate.
Bottom Plate Repair
1. Drill 6.3 mm (1/4") hole at crack termination.
2. Center plate 16 mm (0.630") from each side.
3. Position 75 mm (2.95") from the end of the bottom plate.
4. Weld in new plate. Do not weld within 6 mm (1/4") of the edge.
Illustration 3. Bottom of Boom near nose.
Crack
~ 75 mm (3.0 in)
~ 16 mm (.16 in)(from each side)
6 mm (.25 in) fillet all around
Illustration 4. Bottom Reinforcing Plate. Make from structural steel.
COPYRIGHT 2001 CATERPILLAR
ALL RIGHTS RESERVED