For the Honeywell TFE731-2 through-5 family of engines that are post Service Bulletin TFE731-72-3596/TFE731-72-3597/TFE731-72-3662/TFE731-72-3741, only oils Mobil 254 and BP/Exxon Turbine Oil 2197 are approved. These oils increase resistance to coke formation on carbon seal ring surfaces.
For the TFE731-20/-40/-50/-60 family, the Light Maintenance Manual (LMM) specifies the same oils as above and therefore it must be used to maintain warranty and Maintenance Service Plan (MSP) coverage.
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