I have a 2011 f250 4x4 4dr 6.7 longbed and i would say over last few months but seems more noticeable within last few weeks, but when i accelerate from a stop i feel a vibration bad in my feet and now when i'm on the hwy i can feel it still in my feet and seat. It's not death wobble i know that my u joints at carrier bearing move freely and rubber on carrier bearing is still together and when spin carrier you can hear the bearings in there, is that the way it should be? Also when its mounted i can move driveshaft up and down and left and right bout maybe 1/2 in and i have 235k miles and running 33x12.50 nitto trail grapplers and this is my second set and never had this issue with first set so i dont believe it's tire issue. Also when i turn and ease on accelerator you can really feel it in the floor. Anyone have a thought on what or if it is the bearing? i just figured since rubber is not torn that it's still good and that flex is normal for ford. Oh and as far as i know everything on driveshaft is still factory

 

Did you check the motor and trans mounts?

 

Yes and the vibration is most when I first drive it for the day and it sounds and sometimes feels like it's somewhere in the front left about bc it'll low tone vibrate so bad that it'll go up into the dash from underneath and I've replaced shocks and tie rods and gonna do driver side ball joints tomorrow. Both vacuum seals and dust seals have also been replaced

 

I've got another description that may help you on pointing me in right direction on where to start looking. My replacement grill guard I tightened the ever lovin **** out of it the other night just incase that had something to do with it which was still tight be but now when I start my truck on the driver side around the fender where it wraps around headlight you can see the vibration in it bad and definitely feel it but you touch my fender and nothing. Hope that gives u a bit more info to where you have a thought on what could be. Thanx

 

Hi chuckie,
I'm a little confused with the descriptions you are describing.
If I understand it correctly, you are feeling something described as while siting in the seat. That would be coming from the rear of the vehicle.
Then you describe a vibration you see up front and yet you cannot feel anything abnormal from the fender area.

It would seem there is more than one problem. Did this problem show up after the tires were replaced?
Would like to offer some things to check, but I need some help too. What do you say ? Thanks

I wanted to explain why I asked about the tires, There is a small line near the side of the tire near the bead that shows if the tire is mounted centered on the rim.
If the space between the rib and rim is not even all around , it could produce an unusual ride which might show up as vibration.

 

Sorry about that and no it's been like that b4 got tires. I've now replaced all ball joints, tie rods and carrier bearing, I have fluid in transfer case and rear end and the vibration I feel is when foots on gas pedal and is most when cold start it and if it's in gear and foot is on the brake I can feel it all thru the floor and even up in my dash will vibrate and if I were to turn steering wheel back n forth as soon as there is tension on wheel u can hear and feel the vibration be more and feels like it's front driver somewhere. When I'm parked my grill guard on driverside when it wraps around vibrates real bad now that I've gone and tighten the bolts even more, which u can also feel in the coil spring, tire and grill but you lean against fender and there's no vibration. Reason I'm saying driver front is bc if I'm going down the street if I hit a bump or anything that makes my suspension flex when it comes back it feels almost like if you had a blown out shock and your truck bottoms out on frame. I don't know what else on front I could ck or replace. Someone had mentioned motor mounts but I've only got 239k on it but Since I'm still somewhat fairly new to Ford how do the motor mounts hold up? My previous truck was 05 Duramax and sold it when had 368k and never touched motor mounts so that's why I'm not sure it could be that but if so how do you ck a motor mount? I've already had to replace all body mounts 2yrs ago

 

Easy way to check motor mounts is,, foot on brake, trans in gear, apply a little throttle and with the hood up you should be able to see if the engine moves up a little or a lot.
If a lot , mount oi shot and you have metal to metal transferring engine pulses to the front of the vehicle..

A little side note, jack rabbit starts can rip the rubber mounts apart with no problem.

 

Thanx I'll have to go try that here in a bit, I had seen the rubber bushing still in there when I took a sneak at it from underneath back by transfer case. No jack rabbit starts here she still stock and always carrying my red heeler on toolbox lol.

 

What would you consider alot of movement? Bc about 1,000rpm the motor flexes up on driverside about 1/4-1/2" maybe

 

That is not a lot.
The best way to check the rubber mount at the back of the trans is with a pry bar . If you lift up the trans you will see right away if the mount separates.