Just like the title states. I am getting a slight vibration and the thunk when going off the throttle and back on quickly. Checked front driveshaft and all is well. Ujoints are original as far as I can tell and feel tight from underneath but look pretty ragged. I'm gonna try to get under there and get a closer look tomorrow. They are a very common ujoint (my 98 Ranger takes the same ones) and I have a "Super Strength" set of each. I'm just trying to decide whether to use the greasable or not.