My 2003 Ford F150 Supercrew Lariat had "the rear end whine" at 40 mph & again really bad at 75+. I intended to take it in before warranty expired but hadn't had time. (Dealt with dealers before and figured they'd just tell me to go away unless something was broke.) Then at 26,000 + miles a grinding noise began & steadily grew worse. Ford diagnosed it as a faulty rear differential. I told them about the whining at which time they told me the noise was "under investigation" & added "the whine had nothing to do with the faulty differential." They replaced the carrier bearings, flushed the housing and reset the backlash, at least it says so on their invoice. I am now aware of TSB 17087--not sure if I should pursue rear axle assembly replacement. Whine is still there bigtime and I'm afraid it might be related to cause of differential failure. Anyone with like experience?