Crown Victoria Police intercepter problems

I have a 1997 Crown Victoria Police intercepter with the 4.6L engine, and automatic transmission. It has a little over 160K on it.
My problem is that when you first take off, the transmission neutrals out and then grabs first, but doesn't do it in manual low. Then when you get up to speed, around 30 - up, The transmission then starts hunting gears making the car buck and jerk every 2 or 3 seconds.

This is where my question gets interesting, I've exhausting tons of time and money and come up with nothing.
First, I've changed the transmission 3 times, with new electronics and torque converters, with no change.
2nd, I've changed the PCM and had it reprogrammed through ford with the factory upgrade for police intercepters and no change.
3rd, I've checked the whole wiring harness, power and ground leads, all check out, with no shorts or opens circuits.
4th, I've replaced the TPS sensor, the MAF sensor, ECT sensor, Both Speed sensors, and oxygen sensors, with no change.

This is what drives me crazy the most, I have not one singe code set, and ford say's that all the sensors are reading accurately and the computer is commanding correct line pressure and gears. I've took it to 3 ford dealers to make sure that I didn't run into a idiot along the way and all say the same thing, " They've never seen one act like this!"

I would estatic if you could atleast lead me in a new direction, cause i've checked just about everthing that has anything that has to do with the transmission. Thanks in advance for info given.