Hi my name is Dave and I have read alot of posts on here and have found some helpful information and tips. My question for all is I have a 2004 explorer xlt push button 4wd and I'm having a problem when the vehicle is in gear drive or reverse with my foot on the brake the driveshaft is rocking back and forth causing the vehicle to lunge forward and back mildly. It will drive fine and shift thru all the gears no problem. The issue is only when stopped in to gear??? This also seems to affect the park gear as I can slightly push the vehicle like it's not fully locked in park??? I've had several people and shops look at it and I'm stuck with same problem. First diagnosis was the rear end was bad....? That didn't make sense to me so the second was at a transmission shop and they said the transfer case was bad and a $1300 fix. Unfortunately not really in the budget so I had one of my personal mechanics do the transfer case swap for alot less $$. The same issue is still there. He tells me to take it to another transmission shop for a new diagnosis. He believes it's something inside transmission? I Believe my trans is good because it rides and shifts smooth although it's possible there is something not telling it to stop completely when I'm stopped in gear? Please help! I've tried to Google this issue and have found no one on the internet with the same symptoms??