Sorry for your problems,
I rebuild transmissions, with the 722.9xx, the whine either comes from the front pump/front bearing, or a bearing from the built-in transfer case not getting enough lubrication.
The 722.6xx and 722.9xx use the same front pump, and the torque converter, but with the 722.9 it appears the bushing bearing on the front pump is getting stuck to the torque converter. If this problem with the front pump is caught very early the only thing that it will need is a revised front pump with a roller-bearing and a new torque converter. The front pump is about $500, and a excellent rebuilt torque converter is about $200 at wholesale...Most cases the damage extends into the transmission, and destroys some front Hard-Parts..
The transfer case bearing has to be replaced, and new oil lubrication passages have to drilled-out. On the 722.6xx 4-Matic vehicles the transfer case can be separated from the transmission, and those transfer cases do not suffer from lubrication issues...
Your best cost-effective approach is to contact Sun Valley Transmission. They will inform you what you can do, and they will ship to Canada, and find a indie shop that can replace the transmission.
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I helped a friend from the USA that his W140 722.6xx broke down near Vancouver Canada, and I coached a repair shop how to do the start-up..
Here is You tube on the front bearing issue:
All the best to you,
Martin