INSTALLER A. 9S6030 - 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
Illustration 1 g06206006
(A) 129-6425 Pinion Shaft
(B) 100-7418 Bevel GearScuffing/Scoring may occur in 129-6425 Pinion Shaft (A) and 100-7418 Bevel Gear (B) of differential and bevel gear group on certain 992K and 854K Wheel Dozers. The scuffing/scoring may lead to increased levels of iron in Service Oil Sampling (S O S) samples. Increase in the level of scuffing may lead to failure of gear set.Solution
Caterpillar is aware of this problem, but an interim repair has not been defined.Refer Reuse And Salvage Guidelines, SEBF8193 , "Reusability of Drive Train Gears" under the section Adhesive wear (Scoring) to determine severity of the scuffing. If the bevel gear set does not meet these reusability guidelines, then replace with same part number.Bevel gear scuffing can occur as the result of excessive loads and/or thin lube films. If bevel gear scuffing is found, investigate the following:
Check the application and operation to determine if it is a high severity application or if frequent overloading is occurring.
Check if any axle overheating alarms have been logged, as excessive axle temperatures can lead to thin lube films.
Check S O S oil sample history and current oil viscosity that is being used to ensure that it is the proper viscosity of oil for the ambient temperature range.
In cold environments, monitor axle temperatures and the application before moving away from the factory fill viscosity (TDTO SAE 50). As multiple shifts or continuous operations can result in axle temperatures to be near normal operating temperatures, for which the factory fill viscosity would still be recommended.