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Differential fluid change

Differential oil changed at 5000 miles, 2016 GT PP, 3.73 with torsen.2 track days aprroxiamately 190 track miles. 2 over heat warnings Stock fluid has friction modifier as indicated in service manual without a doubt. Saw steel filings on both drain and fill plug magnets, not a huge amount more of a fine steel paste in the recess around the magnet. Change with 1.5 Liters of Miller Oils 75W90 NT and 3.5 ounces of Motorcraft GL-3 Friction modifier. Easy job, took 20 minutes on roll up race ramps. GT 350 track pack cars should be just as easy. If you drain the cooler by removing the lower hose, you should add about .3L more gear oil and the full 4 oz. of friction modifier. I don't know of any way to trigger the diff pump on without a Ford IDS tool to recirculate through the sump and cooler matrix. Maybe a spare diff temp sensor and a candle to trick it on.
Steve, thanks for the tips!

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