tranny issues -different than what ive read
 

I have a 2006 f150 5.4l AT. My truck is sitting right at 118k miles. Its shudders, doesnt slam, under acceleration, but differently from what ive read. Instead of happening between top gear and O/D, it happens in every gear between about 1600-2100 rpms as i accelerate through that range slowly. If i accelerate hard, as if i skip the range to go to a higher gear and rpm, it doesnt do it. It also doesnt do it if i really really feather it.

So what do you guys think it is? From what ive read it could be the TC, needing ATF and filter, rear diff going out, coils, or plugs, or possibly a combination.

Any thoughts on my particular instance? It sounds different than any other instance ive been able to find so far.

For reference, we also had a 2005 expedition that had the O/D skipping issue going up hills or under load, so i know what that feels and sounds like, and this is not that.

Thanks in advance,