Hi. My Father's 2003 LS460 makes a strong sounding "thunk" under acceleration for about 3 years now. He always complained about it, but recently heard it myself. Usually happens in higher gears but never in OD....and occurs when the car seems to "not be able to decide" between the highest two gears when not in OD. Two service mgrs at two dealerships heard it and are stumped with the thumps. Any ideas? I seached and found advice with a drain and replace using the Toyota fluid...this was done. Still have noise. Anyone have this issue..or advise?
George is in Boston area, I'm in DC.
Chas