Hello all...I have a 2006 2wd XL 4.2 that has been "hopping" in the rear end at around 50-55 mph since i got it (bed bounces like crazy more to the drivers side). I replaced wheels and nothing, rebalanced twice, getting ready to change out all rotors to slotted...I cant think of anything else...tires? Anyone else had this prob?

 

Bad shock?

 

its a ford thing i think i notice them doing it all the time when im beside them on the hiway

 

Mine does the exact same.. Never found out why. From about 45-50 mph, the back will start jumping. Nothing to bad, but shouldn't be there.

 

90% of the time it's a warped driveshaft. Even if it's out by half a degree it'll start bouncing your back end pretty good. You'll notice on the newer models they've gone to an ENORMOUS alloy shaft (no kidding, the thing Is probably 6-8" in diameter), which is hollow(lighter), stronger, and precision balanced.

 

i searched f150 vibration problems once and what i found was astronomical all the problems and complaints all chalked up to the frame being to stiff but i did find that there is a frame dampener kit u can buy that u mount somewhere in the rear of the truck

 

Any info on that dampener would be great!!

 

6-8" in Diameter....your kidding right ...

 

try looking thru ford for the dampener

 

it was three years ago so i dont quite remeber where i saw it but it was 700 bucks...... but i live in canada and we get raped out the *** for parts probably be about 200 bucks in the us lol