Rework of the Blade Assembly{6060} Caterpillar

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

The 268-4156 Semi-Universal Blade As that is used on some D7G Series II machines and the 268-4164 Semi-Universal Blade As that is used on some D6G Series II machines may crack on the top rear of the moldboard and at the gusset on the bottom.

Solution

The cracking of the blade can be eliminated by welding reinforced plates to the front top of the blade and by welding reinforced plates to the bottom of the blade. Use the information below to rework 268-4156 Semi-Universal Blade As and the 268-4164 Semi-Universal Blade As .

Inspect the Blade Assembly for Cracks

Any cracks that are found need to be gouged out and the cracks welded. For information on welding, refer to Special Instruction, REHS1841, "General Welding Procedures". Any bends need to be straightened.

Repairing any cracks and straightening any bends in the blade assembly will not eliminate the cause of the cracks or bends. After any repair work, the blade assembly needs to be reworked in order to strengthen the blade assembly so that further cracks and bends can be avoided.

Rework of the Blade Assembly

Illustration 1	g01885873
(1) 1U-4961 Plate (Right Hand) (2) 1U-4962 Plate (Left Hand)

Illustration 2	g01885899
(3) Small Fabricated Plate (4) Large Fabricated Plate (5) Fabricated Gusset

Illustration 1 and Illustration 2 show the various components that are required to rework the blade assembly. The various components and the required quantities are listed in Table 1.

In order to fabricate the components, refer to""Fabrication of Components for the Rework of the Blade Assembly" ". In order to install the components to the blade assembly, refer to""Welding Details" ".

Fabrication of Components for the Rework of the Blade Assembly

Fabricate the following components from heat treated structural steel with the tensile strength of 1025 MPa (148664 psi) and a thickness of 10 mm (0.4 inch).

Small Plate (3)

Illustration 3	g01886317
(A) 140.5 ± 1.5 mm (5.53 ± 0.06 inch) (B) 270 ± 1.5 mm (10.6 ± 0.06 inch) (C) 15 ± 1.5 mm (0.6 ± 0.06 inch)

Large Plate (4)

Illustration 4	g01886533
(D) 295 mm (11.6 inch) (E) 270 mm (10.6 inch) (F) 10 mm (0.4 inch)

Gusset (5)

Illustration 5	g01886764
(G) 57 mm (2.3 inch) (H) 71.5 mm (2.8 inch) (J) 342.5 mm (13.5 inch) (K) 329 mm (13 inch) (L) 19.5 mm (0.8 inch) (M) 23 mm (0.9 inch) (N) 5 mm (0.2 inch) (P) 280.5 mm (11.1 inch)

Welding Details

Illustration 6	g01887315
(R) 160 mm (6.3 inch) (S) 15 ± 5 mm (0.6 ± 0.2 inch) (T) Weld or grind the surface flush after welding in this area.

Weld 1U-4961 Plate (Right Hand) (1) and 1U-4962 Plate (Left Hand) (2) to the front top of the moldboard of the Semi-Universal Blade Assembly. Refer to Illustration 6 and Table 2.

Illustration 7	g01924181
Location of new gussets (AF) Old gussets (U) 142.5 ± 1.5 mm (5.6 ± 0.06 inch)

Illustration 8	g01888473
(V) 60 ± 3 mm (2.4 ± 0.2 inch)

Illustration 9	g01888596

Use Illustrations 7 through 9 and Table 3 for welding information and placement of the gussets.