The other day, my vehicle jerked roughly while I was driving - I was doing about 55 mph at the time, eased back on the throttle, and the SUV suddenly jerked like I'd hit something. It happened again a few miles later. When I checked the U-joints, they looked good. The transmission fluid is brown, though. I don't want to waste money on a transmission flush if the transmission itself is going to die soon. I know I'm going to have to get the fluid changed anyway, but would old tranny fluid cause my vehicle to buck like that? Or could it be something else?
It’s not likely that servicing your transmission will fix your problem. Without experiencing the problem firsthand, it’s difficult to say if what you have is an engine or transmission problem. Obviously, internal transmission issues can result in a harsh downshift that may feel like bucking when you let off the throttle. However, and engine performance problem, due to a failed sensor or something of that nature, could also result in the vehicle bucking. I suggest you have a trained professional diagnose your vehicle first hand to determine the cause of the bucking you’re experiencing.