FITTING 1178690 - Caterpillar

Illustration 1. 4I-0554 Plate (2)
(A) 25 mm (1.0 in). (B) 10 mm (.4 in). (C) 351 mm (13.8 in).Make from ASTM A370 carbon steel.
Illustration 2. 4I-0555 Plate (3)
(A) 25 mm (1.0 in). (B) 10 mm (.4 in). (D) 374.1 mm (14.73 in).Make from ASTM A370 carbon steel.
Illustration 3. Runoff Strip (4)
(E) 37 mm (1.5 in). (F) 25 mm (1.0 in). (G) 3 mm (.12 in).Make from ASTM A370 carbon steel.Removal Procedure
Illustration 4. Remove Hatched Area With Procedure Below
(H) 720.5 1.0 mm (28.37 .04 in). (J) 654.5 1.0 mm (25.77 .04 in) typical both sides.1. Remove 70 mm (2.8 in) of the 8 mm (.31 in) fillet weld (N) back from the joint between the boom nose bracket and the main part of the boom assembly, four places. This weld is shown in Illustration 5.
Illustration 5.
(N) 70 mm (2.8 in) of 8 mm (.31 in) fillet weld.2. Index boom 180° on it's longitudinal axis. This positions the boom in an upside down position.
Illustration 6. Position Of Boom For Cutting Weld3. Use Illustration 4 to establish the location of Dimension (H). Remove the cross weld that secures the nose bracket to the bottom plate of the boom. Use an air-carbon arc method to remove this weld.
Illustration 7. Detail View K
After weld is removed grind to (P) 25.0° + 5.0° - 2.0°. Take extra care not to penetrate the side plates of the box section.4. Index the boom 180° back to its normal position.
Illustration 8. Boom Position For Step 3 To Cut Away Weld5. Use Illustration 4 to establish the location of Dimension (J). Remove the cross weld that secures the nose bracket to the side plates of the boom. Use an air-carbon arc method to remove this weld.
Illustration 9. Section View L-L
After weld is removed grind to (P) 25.0° + 5.0° - 2.0°.6. Use Illustration 4 to establish the location of Dimension (H). Remove the cross weld that secures the nose bracket to the top plate of the boom. An air-carbon arc method is needed to remove this weld.
Illustration 10. Detail View M
After weld is removed grind to (P) 25.0° + 5.0° - 2.0°.7. Prepare the boom assembly by removing any remaining pieces of the back-up plates. Do not gouge the side plates, top plate, or bottom plate of the boom.Optional Designs
Illustration 10. 118-5925 Bracket Assembly With Forged Brackets
Illustration 11. 118-5925 Bracket Assembly With Fabricated BracketsUse Installation procedure below for both designs.Installation Procedure
Illustration 13. Position Of Plates
(2) 4I-0554 Plate. (3) 4I-0555 Plate.1. Tack weld the two plates (2) inside the top and bottom edges of the boom body. Do not place any tack weld within 20 mm (.8 in) of the end of the back-up plate.2. Tack weld two plates (3) on the inside of the side edges of the boom body. Do not place any tack weld within 20 mm (.8 in) of the end of the back-up plate.
Illustration 14. Position Of Bracket On Boom
(1) New bracket assembly. (R) 2689.0 3.0 mm (105.87