STONEGREEN

I have an 09 F-150 with a 4.6 & an overdrive transmission. I got it 15 months ago with 23K miles and have put on 11K miles to date. The maintenance schedule says to do transmission maintenance at 60K miles. Normal mileage these days seems to be 12K - 15K per year, so if that's the case, a truck this age would have 72K+ miles on it and would have had trans maintenance a year or so ago. Does the age of the vehicle come in to play here or is trans maintenance based mostly on mileage? We tow a popup camper, 1746 lbs, and schlep along a few hundred lbs of gear, a few times during the season. Next year we are planning a trip from NW Ohio to upper Maine and will be putting on 2300 or so towing miles, mostly on the Interstate and through the mountains. I did have an auxiliary trans cooler installed. Should we move forward with the maintenance before hand and switch to synthetic fluid?

Comments & tips greatly appreciated.

STONeGREEN