Today I put the truck in reverse and I heard a loud rattle coming from under the front of the truck. It only does it in reverse. Everything sounds just as smooth through drive and neutral, but as soon as you shift into R, the rattling starts.
I think it may be the tranny, but I am not the best at diagnosing these types of things-- I thought maybe someone here could help!!

 

It sounds like you have the same thing I had. When you put the truck in reverse it sounds like you are dragging a metal garbage can under the front end? That is what my truck sounded like. Also, it would not engage reverse smoothly.

I tried to get the truck to the dealer but it didn't make it down my driveway. The whole drivetrain froze! Didn't even have neutral. They had to drag it onto a flatbed. Ford installed a whole new transmission.

If you need to be towed, call the 800 roadside service number. They will arrange the tow and it will cost you nothing within 35 miles. Also, ask for a loaner. They won't volunteer it but gave it to me when I asked.

Good Luck!

 

My rattle does'nt seem as drastic as yours, but when i give it gas in reverse, it sounds like a heat sheild rattling. I've been under the truck but can't find it. It might be coming from the tranny...

 

I drove it quite a bit today, and didn't notice the problem at all until late this afternoon. I can't figure it out. I would take it to the dealer, but there isn't a dealer in the area that is willing to help me! I had the truck in for the belts squealing when the truck shifts, they tried to charge me $35 because they said it was the Airraid intake, and that is what was causing the noise!!

If it locks up on me, then it will be a little easier to "explain" to the dealer that this is not related to aftermarket accessories.