My truck is a 2001 Ford F150 4x4 with the 5.4 I first noticed this vibration when driving it sometimes. All of sudden it would vibrate for like ah couple seconds as if I just ran over a rumble strip. It didn't bother me much so I ignored it, I then cranked my torsion bars an the vibration got worse. Now at highway speeds it is a constant vibration but only when I accelerate. So when I press the gas it vibrates an when I let off it quits. I feel vibration in the steering wheel when it vibrates an it sounds as if the vibration is coming from the right front, same location when it used to sound like I ran over a rumble strip. I'm thinking bad u-joint? Any ideas or things I can do to troubleshoot please tell me. Thanks

 

always rule out the simple stuff 1st....make sure you don't have a bad tire or bent rim, lug nuts are all tight, air pressure is where its suppose to be, nothing snagged under there..etc

then you'll need to start looking closer at the tie-rod ends, ( inner and outer), sway bar end links & bushing, upper & lower ball joints....Oh don't for get the brakes, maybe ya got warpped rotor.....then maybe wheel bearings

 

Mine was a sticking caliper. After a long drive feel the wheel and if one side is hotter than the other if so then you have a problem. Could be wheel bearings but those usually make noise.

 

When my u-joint went bad I had the same rumbling vibration. Felt like it was coming from the back of the cab. When you let off the gas it stopped.

 

get your tires checked/balanced if it has been a while. I had the sticker weights fall off because the kid didn't clean the inner rim well... rough ride at acceleration.

I would get 4oz fiction modifier from ford and squirt it in the rear diff.

really need more info on how you drive, where, conditions etc.... if you had them under water the diff's need oil changed.

do you have LS? the clutches need the modifier, and it does break down after time.

2001? you shouldn't need Ujoints. . . but again...how many miles...? need more data to support a fix.

go cheap first. 4oz is only 8 bucks.... just remember to put the fill plug back in the diff.

 

Well I took out the rear drive shaft an the u-joints were shot, so I took it down to the local driveshaft shop an got some spicer u-joints put in an all is fine now. Plus those were the original u-joints they had about 250,000 miles on em (current mileage of the truck). Next comes replacing the front driveshaft u-joints, I'm sure those are worn out too. But thanks everybody for giving me suggestion. I appreciate it!