Some of this is similar to what I had with my TBird. At time I got a shutter when it shifted or going up a incline, but not all the time. Found the pan full of metal, had to have it rebuilt. Then about 10 months later it was as if you put it in neutral for a few seconds while driving down the highway. They finally got that tracked down to a intermittent short in the computer. It would short and tell the tranny to go to neutral. Had a heck of a time getting that to happen when a tech was present. They didn't mention using a recorder either.
97 XLT Extended Cab 4X2, Northland Edition Short Box. Dark Toreador Red & Saddle Tan Accent. Tan Interior. 4.6L V8, 4-Spd Automatic. 3.55 Limited Slip differential, ABS, Factory Mag Wheels, Factory Bedliner, Non-Leaking Sliding Rear Window, Trailer Towing Package, LeBra Tonneau, Ziebarted, with Repaired Crack in the drivers door.