I have a 2004 Screw 2wd, recently I had new BFG AT KO's installed on factory wheels, 2.5 inch Daystar leveling kit and 2 inch rear block added. Tires are 265/70/17. Had the tire work done by a tire shop I have used for years thats always been really good about getting the job right the first time. Lift work was done by an ex Ford mechanic. The thing is I am getting a shimmy or vibration most noticable between ~20-25 mph, not severe, but its there, then goes away as speed increases to the point where its very smooth at highway speeds. This was not there before the new tires or lift were put on. Pretty sure it has nothing to do with the leveling kit, but not as sure about the rear blocks. I thought maybe the change in driveline angle might be partially responsible. So my real question is, do you all think a tire can be unbalanced enough at low speeds to create a mild vibration, but smooth out as speed increases, or should I be looking else where for my answer???? BTW I have played around with tire pressures and even rotated them, no noticable change.

 

It may be a driveline vibration if rotating the tires had no affect on it.

 

I am starting to think that too Wandell. Its not always the same severity or exact speed, throttle input seems to have an influence on it as far as I can tell. I was thinking maybe the dampener between the two sections of the driveshaft is the culpret but its really hard to narrow down. Thanks for the input.