2004 Ford F150 Any Ideas

I own an 04 Ford F150. For about the last 6 month, everytime I engage reverse in stalls/hesitates. If I wait for @ 4-6 seconds after engaging revers it shifts just fine but if I engage in reverse and give it gas it slips and then kind of engages hard into reverse. I do the regularly scheduled oil changes and take care of my truck. Other than taking it in, is there any operator level maintenance taht I can do to resolvethis problem?

V/R,

SFC Tim Stanton
US Army