I'm going to suggest 3 possibilities, firstly I don't think it's the transmission at all but rather the wheel-bearing! Generally to test for wheel bearing if you are doing about 10 or 20 mph you move the car to the left and right (not violently) and there will be a change in the hum or noise and if it's to the point of grinding and crunching then it is beyond the point that it should have been replaced. If it breaks you will not be able to put the car in park. If a cv joint breaks it could also cause damage to other parts such as the oil pan..
2nd suggestion perhaps is that it is a constant velocity joint (CV) or the axle as you may call it - although one would hear clicking sounds when turning and giving it a bit of gas - this would be the outside CV-joint since an axle shaft is comprised of 2 CV-Joints (inner and outer)
3rd, and least likely is that where the cv-axle goes into the transmission there is a brass bearing or bushing and this is worn.
In some vehicles the brass bushing/bearing is changeable but not an easy task. Dealer inquiries may be necessary for this info and part availability. Generally when there is transmission problems in these low-end cars (not a mercedes, bmw etc...) the transmission is typically changed. There are many local websites like
www.kijiji.com or
www.kijiji.ca here in Canada, that you may find parts and local junk-yards and mechanics etc., that you won't find in your phone book. This website can perhaps save you money.
Considering a possibility of problems inside the transmission, I would remove the fluid, then remove the bottom pan and inspect for filings and grey bits of fine residue or even silver chunks of metal at the bottom of your transmission pan. This and of course the color and smell of the transmission fluid are indicators of serious problems.
Contamination, dirt, and especially heat are killers of transmissions.
Aftermarket coolers (the little radiator typcally in front of all the other radiators eg for the engine cooling and the air-conditioning although some transmission coolers are part of the Engine coolant radiator). Aftermarket coolers help keep things cooler than the factory ones and are used for racing and/or if you haul trailers etc.
Just noticed that you stopped the wheels while on the stands, so Hmmmm??!! That definitely sounds like inside the transmission or perhaps the torque converter bolt has come loose but no, you would hear sounds all the time. Sounds to me like you are going to be experiencing some problems in the near future.
Ha, not sure if you remember the days of the Ford Taurus and the overdrive issues they all had, in fact most overdrive vehicles had problems for years. Well I got this Taurus - 1998 model or something and the transmission was shot, I found 3 different burnt out transmissions from different junk yards and tore them all apart and rebuilt one from them all. There was one set of clutch-packs that I couldn't change and they looked fairly bad and burnt but when it was all back together the car chirped in between gears when you were giving it to her. Sounded beautiful, and worked awesome but I couldn't sell that car for $500.00 because of the notoriety these vehicles had.
Some other problems that I noticed inside these transmissions is that some of the clutch packs which just fit snuggly inside the transmission had vibration to them and were wearing out the inside of the transmission housing. There were of course bits and chunks in the pan.
The ones with the clutches burnt were not so bad and did show small signs of vibration and small wear marks inside the housing were there but one was worse than others. I was able to salvage the clutch disks from all of them and just interchanged the bad ones with the good ones, put in the proper fluid (Be careful to use proper fluids as I believe it is Ford that may be different than others) and the vehicle worked like brand new practically.
In short, if you have the tools, time patience, and of course the parts, you can do this for next to nothing.
Perhaps some videos of your problem are available on
www.youtube.com You can probably get a better idea from there.
I'm not a transmission specialist but thought I would give you some indications of steps and hints to resolve your problem easier.
Maybe someone else can give you more info as to that noise but I can only say that any noise from inside the transmission is not good.
Hope this helps a bit.