monkeyboy99

Check this out. We went four wheeling to test out my '09 FX4 (SCrew short bed) a little and as we were heading home we heard a rattle in the rear from underneath. We checked as well as we could and didn't see anything and there was no rattle on the paved road to home. When we got home I crawled under the truck and found this big hunk of metal attached to the rear left frame bolted to the top of the frame between the frame and the bed. One of the weld nuts on this thing had broken loose and it was bouncing around between the frame and the bed. My major question is - what is this thing? What you see in the attached photo is all there is (there is no mate on the right side.) There was nothing else attached to it and all it appears to do is bounce around on the frame. Is this some resonant dampener? Do any of you other FX4 owners have this? It's on top of the frame between the frame and the bed, just forward of where the leaf spring rear bolt attaches. It's kind of hidden from the outboard view, but real easy to spot when your spare is lowered. It's about a foot long x 1 1/2" high x 5" wide and weighs about 15-20lbs.

My other questions are - what would the Ford dealer say if I brought this in and asked them to fix it? What if I just left it off?

The blue in the photo is just tape to keep the bolt from sliding out. The last three photos are of the weld nut that busted loose.

Any help is appreciated.

Stephen

Ford Fx4

I have the same thing on my 09 fx4 too...I think all the trucks have them though.


I am sure it is an important piece and I would get it fixed. It has it's own name for it, which I can not remember off the top of my head but is has to do with controlling road vibration/nibble

1sweet09fx4

Mine has it too. never heard the rattle yet

Franchi

That's odd. I have no idea what that is....lol

texasrat

ups

texasrat

thats what it is, ive put them on the 2004- 07 f150 that were 4x4. when i worked at ford.they are having vibration proublems still . ive put some of them that where 20-30 lbs. the early model ones were round hunks of steel with a rubber center, like a giant motor mount, and we hade to trill the frame to put them on, what fun it was!!!!!!!

seadoons

Looks important! Are the above posters saything that this thing's sole purpose it to keep stuff from rattling / vibrating?

texasrat

google f150 frame dampner!!!

sharper4

Take it in. They don't have to know you were rough-riding your truck. It has a bumper to bumper warranty. Just tell them whatever and see if they'll fix it up. There's no evidence of an accident or anything, is there? Its a pick-up truck, I'm sure they expect you to be off road from time to time or hauling things.

Ford Fx4

There you go, that what I was trying to think of.

Frame dampner it is!