2004 Ford F-150

Noises problem
2004 Ford F150 V8 Four Wheel Drive Automatic 88000 miles

I have a clicking noise coming from what I believed was the torque converter. Had it replaced and the noise still exists. The noise is relative to the vehicle's speed, not engine and only occurs when the torque converter is unlocked. Noise is gone once locked up. Seems to be worsening over the past couple weeks. The clicking noise also isn't noticeable until 25 mph roughly and even then it is not a distinct click until I go faster. Thought it was fins on TC touching but apparently not. I have also noticed if the TC is locked in O/D @ around 45-60 mph and I start pushing on accelerator it will shudder as if thinking about shifting down (or at least unlocking TC) for a brief moment. Could all this be from a TCU or some other sensor? The reason it is hard for me to believe this is that at slow speeds the click is softer - not quieter, just less sharp. If it was an electronic click I would think its frequency would be the only change. Transmission shop said tranny was good and that thrust washer in old TC was wearing - good to have replaced early on. I'm beginning to wonder if there was anything wrong with the TC at all! Clicking noise also is not affected by steering or use of 4x4. I've read of Ford's clicking in 1st gear but this is in all gears. Any help is much appreciated.
March 3, 2010.

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