Weird Vibration I cant track down. Help!

[ccbruin]

I have a weird vibration in my truck, and a "loose" feeling ride. It's not suspension or tire related i'm 95% positive (new ball joints, tie rods, rack and pinion, alignment, shocks front and rear). Feels like something is out of balance (hard to explain), but since it happen at low speeds i figure if something was out of balance it wouldn't really have any effects until high speeds/rotation. It happens at nearly every speed even slow speeds. I am starting to think its the drivetrain and maybe the transmission. I can feel it under my feet and through the steering wheel. I'm pretty stumped right now, i thought it was something in the steering so i replaced it all, but to no prevail. Do you guys have any ideas?

Edit: '06 F150 4WD with fabtech lift

[Chris]

Driveshaft out of balance would be my guess. Have you checked your u-joints?

[ccbruin]

An out of balance driveshaft wouldn't have a very much affect at real slow speeds, would it? I'll have to check U-Joints, those have been in the back of my head..

[Robert B]

if it is the exact same in every gear and relies mostly on speed for any change it does have then yes i would say tcase down and a driveshaft that is far enough out of balance will do it all the time and still look pretty straight to the naked eye ..check for any weights that were added to it that may have fallen or been knocked off too

[Rick]

if it is the exact same in every gear and relies mostly on speed for any change it does have then yes i would say tcase down and a driveshaft that is far enough out of balance will do it all the time and still look pretty straight to the naked eye ..check for any weights that were added to it that may have fallen or been knocked off too
my bet.....ujoints

[The StRanger]

An out of balance driveshaft wouldn't have a very much affect at real slow speeds, would it? I'll have to check U-Joints, those have been in the back of my head..

More low speed than high !!
And !! X2 U joints !!

[zukrider]

first thoughts to come to mind are the torque converter or a front cv. when the inner cup wears and gets loose, will cause a vibe under load, but not at coast.

[carpenle]

maybe tires out of balance.

[ccbruin]

first thoughts to come to mind are the torque converter or a front cv. when the inner cup wears and gets loose, will cause a vibe under load, but not at coast.

It still occurs while nit under load, when coasting. That rules out the torque converter or cv?

[ColoJeeper]

Rotate your tires and see if the symptoms change any...

[The StRanger]

It occurs while nit under load, when coasting.

That lets out U joints

[gm4x4lover]

Rotate your tires and see if the symptoms change any...

This is excellent advice. I would rule out tire balance but not irregular tire wear or a bad tire. If you feel it in the steering wheel then its direct connected to the front end of the vehicle. Look for a bent wheel, odd tire wear, and inspect the front cv shafts.