[vncj96]

I would bet it was done on the cheap or by a inexperianced individual and the angles werent adjusted correctly, this can stress all suspension components along with the driveshafts and u-joints. Also check your driveshafts, if this truck was lifted that much the previous owner may have actually done some offraoding and the driveshafts could be out of balance, there should be little tabs on them just like on rims that balance them. Honestly this is a good reason to never buy a used lifted modern day truck, you just dont know what morons (even dealerships) have done to save on the high cost of IFS lifts.