I have a vibration. Its not always there but when it is, it shows up while im accelerating and starts around 25 mph..I just replaced the rear ujoint and ever since then Ive had these vibs. I went under and tightened the bolts and its still there. Im not sure if its the ujoint tho because when i let off the gas the vibs stop. My bro said it could be the torque converter going bad but im not sure.. Anyone have any idea whats going on?