Hello all. So i was on the highway today and i noticed that my car does an awkward sputtering in 5th gear, ill be going 65 mph. and if i step on it, or gradual accelerate it is a weird shaky acceleration, not smooth at all. and it happens in 3rd and 4th too. Do you think it could be the U joints? Driveshaft, or maybe something like tires needing balancing? Im not sure. but thank you for all/any input.