Its probably just low on fluid. The last time mine made any noise (and was low) I just added a little bit of transmission sealer and its sounded fine ever since. I've always used transmission fluid in the place of power steering fluid, (but no the other way around) and have never had a problem. Another alternative could be to go to an oil change shop and have them suck out the old fluid and put new in. How many miles are you up to?
New Toy - Custom 92 GT soon to be a turbo beast
DHG 01 Bullitt - JLT, Mac o/r H, MGW, Bama tune, Focus pump, 3.73s, DRs best 1/4 13.50 @ 101 best 1/8 8.53 @ 82
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2011 F-150 Supercrew Ecoboost