BOLT ASSEM. 3Y6037 - Caterpillar

oils acquire wear metals and contaminants from friction materials, loaded gears and bearings, and passage around oil seals. Some dirt and moisture can also enter from the atmosphere through breathers if equipped.Transmission filters are available in Standard, Advanced, and Ultra High Efficiency. Many lower powertrains, such as final drives, differentials and axles may not use filtration. Some do have filtration.Off Board filtration is recommended for large systems. Refer to this Special Publication, "Oil Filtration Carts".Particle count of powertrain oils to determine cleanliness is recommended. Filtering of the oil that is filled into the powertrain compartments is recommended to achieve a cleanliness level of the oil of "ISO 16/13". Refer to this Special Publication, "Contamination Control" for details on the contamination requirements and ISO code information.