Idr if Iv had this problem for a while or not, but tonight I was adjusting my kickdown, so I was listening to the truck with the radio off, and I noticed that in overdrive with maybe 1/16th consistant throttle @ about 50-55ish it is surging. Is that just due to the ammount of load at that speed/gear+the lack of throttle, or does that sound like an underlying issue that is accented by the extra load, and should therefore be looked into?