I recently purchased an 07 f-150 xlt and right from the get go it had a "bounce" in the rear at about 54mph. Acts just like a tire out of balance. I had them put new tires on it. No good. Had them balance then road force balance. No good. Put two new rims on it, no luck. The Ford garage says everything is tight. Asked them to check shocks, tranny, drive shaft balance, u-joints ect. They said they checked everything and all was fine. I am losing hope that they will be able to find the problem. Does anybody have any ideas? What else could it be? Any input would be great!
Thanks

 

is it a massive bounce or just a small little bounce that you noticed and now cant unnotice? i think all of these trucks have a small bounce due to the way the bed is attuched to the frame or something like that. My truck has always had a nice bounce and i just got new tires and balanced and it has greatly decreased the bounce almost completley but i do that that little sweetspot where it will happen.

 

It varies. Some times I can barely feel it, and sometimes you can see the bed bouncing like crazy. I have noticed that the bed seems to be awful "jumpy" like they have loose bolts or something! But Im afraid it might just be one of those things like you say, something that I cant unnotice

 

My explorer use to bounce, but i had a bad shock.

 

My bed is bouncy on my '07 XLT also, but never can feel it in the ride.

 

I notice the same bounce, at nearly the same speed, in my '08. For some reason, it will vary in intensity depending on which type of road surface I'm on. Smooth asphalt is the worst. It's very noticeable while driving, and I can't imagine how embarrassing it looks from outside of the truck. I'm pondering upgrading the shocks, since the rear has always felt a bit too "floaty" to me, so this may be related.

Wasn't there some TSB about this vibration issue? Something about Ford would bolt/weld a gigantic metal block to one of the frame rails, in the rear.

 

I do not notice any bounce in my FX4. I have noticed that my new tires have greatly improved the ride. I used to be able to feel every bump and expansion joint. The new Firestone Destination ATs have made a big difference.

 

It is most likely a bad torque converter. Try turning overdrive off, if this stops the bounce then you have your answer. I had the same issue with my 05 it was about a $500 repair, I am told that they needed to pull the transmisson to do it, more work than I could handle so I let the shop due it and the vibration is gone. Hope this helps.

 

Well that would suck! But it would make sense. Im pretty sure I tried turning off overdrive. I tried everything I could think of like putting in neutral too see if it was the tranny, pressing brakes, going above the speed and coasting down past it. You name it. Ill try turning off OD in case I missed that(been a while since I tried anything) and see what happens. Thanks for the suggestion.

 

^^^ if it is not that then i would suggest upgrading the shock. It will help the bed "stick" to the road better when not loaded down.