Ford Repair: Transmission, 2004 ford taurus, friction modifier

Question
is there any way you could please post the answer for me once again , i was unable to find it thanks againHi, 2004 Ford Taurus 24 valve duel O.H.C when driving trans seems to be fine under normal gas but sometimes at 35 to 38 M P H it shifts very quickly down and back to top gear and is fine once i get out of that speed range it does not do it all the time any idears ? Thank you for your time , Gary

Answer
These trani's have their quirks but not common. I'm gonna assume you've had the fluid level checked ???? If this being the case, go to your local ford dealer or reputible garage. have the entire trans system flushed,, not drained and refilled and have a friction modifier added. you'll know if ( the friction modifier )  was added as this modifier fluid stinks to high heaven.. This should take care of your problem.. please keep me posted.