NUT 2C1553 - Caterpillar

All electrodes must be completely dry. Do not weld in areas where there is movement of air or in temperatures of less than 60° (15°C).
(1) Make four gussets (1) and four gussets (2) from 80.0 (3.15") thick high strength structural carbon steel to the dimensions shown. Use a 25.5Ø (1.0"Ø) drill bit to make hole (A) in gussets (1) and two holes (B) in gussets (2). Make holes (A) and (B) 73.2 (2.88") deep. Use a 1 1/8"-7 tap to make threads in holes (A) and (B) 54.0 (2.13") deep. Make a 30.0 (1.18") x 45° chamfer at location (C) on each gusset. Surfaces (D) on each gusset must be a machined smooth surface, and at a 90° angle to sides (E) and to each side of the gussets. (2) Make four plates (3) and four plates (4) from 16.0 (.62") thick high strength structural high carbon steel to the dimensions shown. Make a 15° chamfer along sides (F) of each plate. (3) Make plate (5) from 18.0 (.71") thick mild steel to the dimensions shown. Make four 31.75Ø (1.25"Ø) holes (G). Make a 57.2Ø (2.25"Ø) spotface on each side of plate (5) at each of holes (G). Make four spacers (6) from black pipe or tubular steel as shown. (4) Four studs will be needed to hold the fixture for the magnetic base drill. If the machine is equipped with 28.5Ø (1.12"Ø) bolts that fasten the carbody to the roller frames, use four 2N5120 or 4L6142 Studs. If these studs are not available, cut four pieces of 1 1/8"-7 threaded rod (7) to the length shown. If the machine is equipped with 25.4Ø (1.0"Ø) bolts, use four 6M2001 Bolts, four 8S2575 Studs or cut four pieces of 1"-8 threaded rod (7) to the length shown. Four nuts and washers to fit the size stud used will also be needed. (5) Make guide (8) from mild steel of any thickness from 3.0-5.0 (.12"-.20"), at the dimensions shown. Put an "R" on each side of one end and an "L" on each side of the other end as shown. These will be used for correct location of the guide when it is used. If this steel is not available a 12.7Ø (.5"Ø) steel rod can be bent to make the same shape as side (X). (6) An extra amount of clearance is needed under the machine for the work to be done. The machine can be put in position over a hole in the ground or blocks can be put under each end of the roller frames. Release the tension on the tracks and use the master pin press to separate the tracks. Lower the tracks to the ground. Lift the machine and put 20.3 (8.0") square blocks between the roller frame and the tracks. Put the machine in position with the boom lift cylinders over the carbody leg first to get the modification. (7) Put guide (8) in position, with the "L" toward the end of the roller