My '98 1500 5.2 auto has a "shutter" when in overdrive, tc locked at low RPM just about the time the tc should unlock (starting up a hill). It's like the tc can't decide whether to unlock or not. It doesn't do it everytime, usually after it does it once or twice, it works fine for the rest of the day. The tc clutch doesn't slip or anything. It's only at the point where it should be unlocking. If I let off the gas then back on the gas, it unlocks/downshifts and is fine. BTW 130,000 miles. Engine runs fine with plenty of power. I bought it new and have always been easy on it (no abuse) I do tow a 5400 lb camper always with OD off. Ideas?