Hi folks, newbie here need some help. I have a 2001 Legacy Subaru GT Wagon. It has MT and 124K miles. I've keep up on all required maintenance and all major service/repair done at dealer.
Recently an intermittent problem has developed. After driving for awhile (~15-20 min or longer) when I turn left or right the car makes a thumping/whumping or clunking noise that causes the car to judder/jerk slightly. This is repeated for what appears to be every rotation of the wheels. The noise/vibration feels in the middle (not isolated to left or right) and is related to the wheel speed (faster the car moves faster the noise). It happens left turn and right turn, and happens when my car is in gear or not (whether I step on the clutch in the turn or not is irrelevant).
I've called a few folks and read a bunch online and the guesses are all over the board from suspension related (sway bar, CV joint, ball joints, tie rod, strut, control arm) to mounts (engine) to axle to differential. I called a few folks in town and they all say things all over the board (some swear it's CV/ball joints another thinks it's diff).
My guess is it's transmission/diff related since it cause the car to shake and only happens after warm up (fluid or metal related after expansion due to heat). There is no diff leak and the fluid seems fine.
Any thoughts?