SHAFT AS 6Y1885 - 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 belowProblem
Tier 4 Interim 950K and 962K Medium Wheel Loaders that operate in waste handling environments are known to have higher silicon (Si) and aluminum (Al) levels in the engine oil.Medium Wheel Loaders in waste handling operations are exposed to higher levels of siloxane gas. Landfill sites and/or transfer stations often times process cosmetic, textile, healthcare, and industrial waste streams. The waste streams have the potential to produce siloxane gas. Siloxanes are organic compounds composed of silicon, oxygen, and methyl groups. Siloxane gas is non-abrasive and does not increase engine wear.In oil sample results, the silicon from siloxane gas may be confused with silicon from dirt entry. However, dirt contains silicon and aluminum. Moderate level dirt entries (silicon and aluminum) are abrasive and will increase engine wear.All engines operating on a site, where siloxane gas is present, will have elevated levels of silicon in the oil. Tier 4 Interim machines working in waste appear to have more silicon in the oil than Tier 3 machines, even when operating at the same site. Some Tier 4 Interim machines may also show low levels of aluminum in the oil.Solution
Operating in a waste handling environment, with elevated silicon and aluminum, can be acceptable, if iron, chrome, lead, tin, and copper are within Wear Table guidelines. Wear Tables have been established for the 950K and 962K Tier 4 Interim engines. The Tables are available on the SOS Services Knowledge Network.950K and 962K Tier 4 Interim Medium Wheel Loaders, operating in waste handling applications should use the Table 1 below for evaluating silicon and aluminum levels.
Table 1
Sales Model     950K     962K    
Product ID Prefix     S/N:R4A, ; S/N:FER,; S/N:J5M     S/N:X4T, ; S/N:FLL, ; S/N:T6A    
Application     Waste Handling Only    
Valid Fluid Hours     250    
Element     No Action Required     Monitor     Action Required    
Aluminum     14     15 - 20     Over 20    
Silicon     30     31 - 40     Over 40    
Valid Fluid Hours     500    
Element     No Action Required     Monitor     Action Required    
Aluminum     19     20 - 25     Over 25    
Silicon     40     41 - 50     Over 50    Note: Silicon will be initially high due to silicone gaskets and silicone sealants used in new or rebuilt engines, and should decrease after the first oil change.