Hello, just picked up an 04 4x4 XLT with the 4.6. I have a short, semi violent vibration upon acceleration that is confusing me.

It only happens from a stop or up to 10 mph if I let off the gas then step back on it fast.

It has a leveling kit with 290/70/18 tires.

Any ideas?

 

I have an '05 4x4 STX with the 4.6l engine and am experiencing the same thing...

Anyone have any input?

 

That could be several things. Axle wrap causing extreme u-joint angles. Torque converter chatter are a few that come to mind.

 

I have a similar vibration with an 2005 f150 more noticeable in the 50-55mph range. Very random and annoying. Dealers can't figure it out either, they recommended new driveshaft but that didn't solve the issue. Have also changed rear rotors, had tires road force tested, and dealer used a vibration annylizer which couldn't pin point the source. Apparently these vibrations are one of most difficult problems for any mechanic to diagnose ?? Very dissapointing to say the least

 

Classic symptom of a driveline angle being out of whack. I assume your truck is 4WD. How big is the leveling kit? If you lift the front of the truck and turn the wheels by hand, do you feel any binding?

 

Yes, it is a FX4 and I do have a front leveling kit on it. However, haven't tried lifting the front to feel for that binding yet though- What would have to be done if it does or doesn't have it ?
thanks