On vehicles equipped with a two piece drive shaft & carrier bearing, there is the potential for take off vibration, depending on the severity, this can be corrected with shimming down the carrier bearing.1-2 hourshttps://s3.amazonaws.com/roughcountry/install/92119700.pdf1999-2016:4WD:Ford:F-250 Super Duty;1999-2016:4WD:Ford:F-350 Super Duty