Above: broken piston
Info Centre >> Fuel and Lube Oil Technical Manual >> 7. Lube Oil - Test Results >> 7.8 Spectrochemical Oil Analysis >> 7.8.6 Lead and Tin Overlay or Flashing
Reciprocating engine:
Bearings; some pistons; bushing and thrust washers.
Final drive/reduction gearbox:
Bearings; bushings.
Hydraulic:
Pump thrust plate; bushings.
Compressors:
Bearings; bushings. Lead may also be present as an extreme pressure (EP) oil additive. Aircraft engines’ deposits from lead containing fuels. Tin may also be present as an oil additive, usually in conjunction with lubricants containing molybdenum compounds.