Re: 2002 XLT trasmission whine
First off, as you pointed out that there is a possible problem with the transmission that was recently installed, the dealer has an obligation to fix it. If need be, get another dealers opinion as Ford work can be conducted at any dealer, not just the one that did the transmission swap in the first place.
Throttle body and transmission are two very different parts. I've never heard of a throttle body make a 'whine' sound. I know my Dodge (which are notorious for trans problems with the band versions (42/44/46RE series). Anyway. If I put my Durango in neutral, the transmission fluid flows through the valvebody, where as in 'park', no fluid is transferred and is therefore a bit noisy when in neutral instead of park.
I just hope the dealer didn't cheapen out and re-use the old transmission fluid. It's been known to happen as the dealers get the money directly from Ford, but instead of giving you fluid they re-use the old stuff and pocket the difference for themselves. Just some food for thought at least.
One final test is to keep the transmission locked out of overdrive and drive at 40-60mph and see if there is a noise difference compared to driving that same speed range with over drive 'on'. RPM's will be higher but the engine can handle it for hours on end without problems so don't let that concern you. If the noise is not present let the dealer know as it might be an over-drive related problem. I'm not positive, but there may be a solenoid that they can change out if that's the case.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!