I have a 2002 Explorer XLT and have had nothing but problems with it. I know have a whining noise coming from the rear end of the truck only when the accelerator is applied. If you foots off the gas there's no noise at all. I was told it could be my differential to to change the fluid. I changed it and the noise is still there. Any other ideas how to get the noise to disappear if it is the differential? Or any other ideas on what the noise could be?