So I've searched hours and can't seem to find anything related to my specific issue on my 2005 AWD 4.7l 2ng gen. It is clunking very loudly and rapidly about 4 or 5 times when accelerating harder than typical. ONLY does it when I am at a complete stop or a slow moving speed, then I would press the accelerator harder than typical and the clunking would happen. Very rapid and noticable inside the cabin, but it quits after a few so it's not constant. And it only happens sometimes, not every time. doesn't clunk when switching from park to drive, so I don't think it would be a slip yoke. I suspect maybe a ujoint but when I briefly checked them, they seemed okay. I believe it's definitely drivetrain related at the front dif but I honestly don't know. I'm not experienced with drivetrains enough to give it a decent guess. With it being AWD, Im really not sure. I did find a leak on my front dif seal where the dog and passenger CV axle meet. Those are intact as well and wouldn't be an issue. i can't find anyone discussing this exact issue so anything would be appreciated.

 

Check Motor mount or Trans mount.