RESISTOR-POWER 5143082 - Caterpillar

Illustration 6 g06326377If a portable bore welding machine cannot be obtained, the bores can be welded manually by hand using the procedure given below:
Deposit several weld passes around the circumference of the bore in the direction of the arrow head as shown in the Illustration 5.
Deposit weld passes at the edge of the bore (D) to ensure both the bore inside diameter and face clean-up during machining. Refer to Illustration 6.Double check the reference measures at the boom foot bearing regarding the specified measurements. If, the bore is out of tolerance, the bore must be reworked to specification considering the following procedure:
Uniformly preheat the area before build-up welding to 100° C (212° F) [Temperature is to be held at a minimum of 75.0 mm (2.95 inch) away from weld in all directions] and maintain preheat during welding. Do not let temperature fluctuate during repair and always maintain this minimum temperature. Temperatures must be monitored and maintained throughout welding.
Reduce the bore diameter by approximately 6.0 mm (0.24 inch).Note: Ensured that the final cut at the bore hole (finished surface) is located within the homogenous, tempered weld metal.
Thoroughly chip and wire brush all welds immediately after depositing. Be sure to add enough weld to allow for complete clean-up.
Blend all starts and stops.
After completion of welding, let repair slowly cool by wrapping in insulating blankets.
Test repair and surrounding area with Dry Magnetic Particle Testing (MT) or Liquid Penetrant Testing (PT) to ensure that there are no cracks.Slow Cooling
Illustration 7 g03824505
Example of a welding blanket.
Immediately after welding is complete, cover the weld with an insulated welding blanket for slow cooling to reduce the chance of hydrogen cracking.Machining Bores
Machine bores back to specification. Use the line boring machine manufacturers procedure and set up instructions to achieve boom foot bore and nose bore as per the dimensions in the below table and in line with each other to a diameter of 0.20 mm (0.008 inch).
Table 5
Description Dimension Bush Part Number
Foot bore diameter 72.980 0.025 mm (2.8732 0.0010 inch) 237-2252
Nose bore diameter 67.975 to 68.000 mm (2.6762 to 2.6772 inch) 9R-9475
Illustration 8 g06325296
Bore centres of the boom foot and boom nose
(D1) 1695 mm (66.7 inch)
(D2) 1535 mm (60.4 inch)
(D3) 1025 mm (40.4 inch)
(D4) 2160 mm (85.0 inch)
(E) Boom nose
(F) Boom footRefer to Illustration 8 to find the bore centres of the boom foot (F) and boom nose (E).Dry Magnetic Particle Testing (MT) or Liquid Penetrant Testing (PT) to ensure that no cracks are present. Also ensure that no other defects are present such as slug inclusions or porosity.If bores do not meet the visual or dimensional inspections in this document, further welding rework will be necessary.Bushing Installation
Note: Bearings must be wiped clean with mild de-greasing agent immediately prior to installation. Re-staking is not required.Lowering Bushing Temperatures
Illustration 9 g06225302
Example of temperature-controlled freezer, box with dry ice but the cooling effect/temperature is limited. Can only be used for pre-cooling, before finally using liquid nitrogen.
Illustration 10 g06225343
Liquid Nitrogen ( −196° C (−320° F))
Personal injury can occur due to