TRAXCAVATOR ARRANGEMENT 8P0977 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, the solution that is identified below may be used.References
ReferenceOperation and Maintenance Manual, "Oil Filter - Inspect"ReferenceOperation and Maintenance Manual, "Transfer Gear Oil - Change"ReferenceOperation and Maintenance Manual, "Transfer Gear Oil Filter - Replace"ReferenceOperation and Maintenance Manual, "Transfer Gear Oil Sample - Obtain"ReferenceDisassembly and Assembly, RENR5138, "735 Articulated Truck Power Train", "Output Transfer Gears - Remove, Disassemble, Assemble and Install"ReferenceDisassembly and Assembly, RENR5139, "740 and 740 EJECTOR Articulated Trucks Power Train", "Output Transfer Gears - Remove, Disassemble, Assemble and Install"Problem
The occurrence of brass contamination in the oil for the transfer gear and/or in the filter for the transfer gear has caused uncertainty about the cause of the contamination. The process of wearing in new components may be a possible cause for the brass contamination.
Illustration 1 g01313236
Typical example of the output transfer gear (1) planetary transfer gear
Illustration 2 g01313253
Typical example of planetary transfer gear (1) (2) 148-9444 Hub (3) 148-9403 Spacer The surface finish on the side of 148-9444 Hub (2) can wear the surface of the brass 148-9403 Spacer (3) that is next to the hub in planetary transfer gear (1). The process of wearing will stop once the hub has found a suitable running position next to the spacer. This initial wearing of the hub against the spacer can be the cause of the brass contamination in the oil system for the transfer gear.Solution
If brass contamination is discovered on a machine with a new output transfer gear or a recently repaired output transfer gear, then perform the following actions:
Change the oil for the transfer gear and replace the filter.
Immediately take a S O S sample of the levels of brass contamination and other particulate contamination in the oil system for the transfer gear as a baseline for a future test.
Operate the machine as normal and take a fresh S O S sample after 500 service Hours.
If the copper level has risen by 50 ppm since the test in order to establish a baseline for the copper level, then remove the output transfer gear in order to determine the source of the copper.If the output transfer gear has been disassembled because of brass contamination in a S O S sample and the cause is wearing of the hub against the spacer, then the surface finish of the hub can be improved in order to reduce the wear.If a new hub is being installed into a output transfer gear, then the surface finish can be improved in order to reduce the occurrence of wear between the hub and the spacer.Improving the Surface of Hub (2)
Remove hub (2) from the output transfer gear.
Illustration 3 g01313742
On one side of hub (2), improve the surface finish of face (X) from 3.5 µm to 1.6 µm. Ensure that the hub remains within tolerance. Refer to Illustration 3 and Table 1.
Table 1
Dimensions for Remachining Hub (2)    
A     1.6 µm    
B