I have a 2013 Charger that will keep locking and unlocking torque convertor while driving. It will lock up at 1500 rpm in first gear (should never lock in first gear) and immediately unlock again. It is really annoying. When coasting in drive at about 50 mph, it will keep doing the same thing about every second. It surges when it does this and the tach will vary about 300 rpm. Other than that it runs and drives great. No check engine light has ever come on. Dealer tried flashing computer but it did not work. Now they want to replace transmission and torque convertor for a phenomenal fee. I don't think it sounds like a mechanical issue. It sounds more like an electronic controlling issue...like something is telling it to lock and unlock at the incorrect times. I cannot find an overdrive button to manually stop the TC from locking up...does it have one? what do you think? any thoughts welcomed. thank you.