Hi, I used to buy a 2006 Suzuki Grand Vitara JT (122k km, 2.0L gasoline and automatic transmission). The car stood in a barn for a year. Now it is the case that when the engine is warm at about 50-58 km/h, when the transmission is in the 4th gear, it starts ratting from the front, as if you are driving over a structured road marking. The transmission then often switches back into the third gear. Someone said that it is on the automatic transmission and I immediately got the ATF should swap and should not drive a single meter more and predicts a capitable gear damage. Now, of course, I am totally unsure.. What could that be? On the cardan shafts I have checked the game before: They are totally tight.