2003 Ford Explorer Transmission Shutters when going into Ov

The concern appears to be the overdrive, however, the actual problem may be the torque converter. If you try turning off the overdrive, does it still do it? Most often, when the overdrive goes out, it simply fails to engage. The most common shudder from Ford transmissions is the torque converter. Unfortunately, the solenoid isn't usually the problem, but the torqe converter itself. Try turning the overdrive off and see if it still does it. Post back with an answer and we'll go from there.

It is possible that low fluid level could cause this concern. The shudder is the clutch inside the torque converter. The computer is commanding a partial lock-up, or a gradual lock-up. Rather than the clutch being on or off, they now are varying in percentage they are engaged. The most common failure is the clutch itself. It shouldn't fail with only 55000 miles, but I have seen them fail even sooner than that, so overservicing should not be an issue as long as the correct fluid is being put back in, that being mercon 5. The reason it doesn't do it when it is cold is partially due to computer strategy, but also because the fluid is thicker and therefore tends to do a better job of lubricating and pressurizing.