Rather than switching transmissions, I think it would be more cost effective to inflate the tires to high pressure, but not too high, and evenly. Check the spare.
It could take a while to get your payback from the transmission change out of your savings on [hopefully] improved mileage.
Take it to Ford for an oil change, and ask them to run you VIN on their proprietary [Ford-only] database of Advisories, Alerts, Memos, Notifications, Recalls, Service Campaigns, TSB’s [tech service bulletins], etc, etc.
And get your alignment checked and maybe a tuneup by Ford.
“…independent mechanics complain they lack the proprietary tools and data to service many late-model cars…” some 2004 models and earlier.
They’r seeking a “Right to Repair” law allowing them access to manufacturers’ databases.
Wall St Journal, Feb, 2011.
Toyota & Ford withhold Technical Service Bulletins from customers & National Hwy Traffic Safety Admin [NHTSA]
"Automakers can save money if owners don’t know about service campaigns that include extended warranties," consumer advocate Clarence Ditlow said.
Toyota alleged it wants to “protect its intellectual property” by withholding the bulletins.
Ford alleged it wants to protect its customers from the risks of do-it-yourself repairs using info in the TSBs. But Ford sells the TSBs to commercial distributors like AllData who resell them w/o restriction.
Mercedes refused to comment on its policy of releasing TSBs in their entirety to the public & govt.