CARRIAGE AR 0366488 - Caterpillar

This instruction gives the procedure for installing the cutting edge replacement parts by removing the former edge and only sections of the corner castings. If there is very much wear, remove the former edge and the complete corner casting. When doing this, make plates from heat treated steel [minimum yield strength 90,000 psi (6327 kg/cm2)] to fill the open areas around the new forged corners and cutting edge. Position and weld the plates, using E7018 electrodes. Weld the edge and corners according to the procedure given in the instruction. (1) Check the fit of the new forged corners to the new cutting edge. Most of the corners fit the complete width of the cutting edge as seen in the first illustration. Yet, on some machines the corners do not fit the complete width of the cutting edge as seen in the second illustration. Use the dimensions of the cutting edge - corners combination as a guide for removing the needed sections of the bucket. (2) Mark the areas of the bucket to be removed. On the smaller machines, 920, 922, 930 and 941, the new forged corners are larger than the former corners. The complete corners and more material from the bucket will need to be removed to install the new corners.(3) Remove the existing cutting edge and the needed sections of the bucket. Check the wear plates on the bottom of the bucket. If necessary, install new wear plates in place of the former plates. (4) Using E7018 electrodes, for all welding, position and tack weld the new cutting edge to the bucket. Keep a .06" (1,5) opening between the edge and bucket. Areas (A) should be the same at both ends of the cutting edge. (5) Position the corners using .09"Ø (Ø2,3) soft iron wire (1) between the bottom of the corner and the cutting edge. Keep a .06" (1,5) opening between the corners and the bucket. Temporarily weld the corners in place. (6) Remove any worn material from side plates (2), making them even with the slope of the bucket. Make two bars (3) to fit the areas removed, from heat treated steel [minimum 90,000 psi (6327 kg/cm2)]. Cut bevels on the edges that come in contact with the bucket. Fasten bars (3) in place and weld both sides using bevel groove welds. (7) Heat the cutting edge and corners on 980, 988 and 983 Loaders to 400°F (204°C). No heating is needed on the smaller machines. Using E7018 electrodes, weld the top of the cutting edge, area (C), to the bucket. See the chart for welds and weld dimensions. Turn the bucket over and weld the bottom of the bucket area (D). Weld from the center of the bucket out, in the order seen in the illustration, to do away with distortion. Clean the welds. (8) Weld the corners in place. See the chart for welds and weld dimensions. Do not let the cutting edge temperature go over 800°F (427°C).