I have a 2011 5 liter regular cab long bed with 3.31 gears that will be replaced with 3.73. I want to start a 28 ft. trailer . I picked up the tranny cooler, t.b.c. and the correct 7 plug trailer harness and fuses. My question is will my radiator be ok or do I need a bigger one? I've read in different articles that ford didn't really make different towing radiators. Is this true? I noticed in the post from N578MD that the 5 liter was not listed.
welcome to the forum! Glad to see the search function turned up a thread you found useful.
As listed earlier in this thread, the ONLY upgraded radiator comes the MAX tow package and i don't think the MAX tow option was ever available with the 5.0L engine.
For what you are pulling, i doubt very much that you would need an upgrade. Cooling doesn't appear to become a problem until you start towing over 9k lbs or so, at least from what i've seen on this forum.
Just for the sake of asking, why the gearing change?
are you towing more than 8,000 lbs?
did you find the 3.31's inadequate?
just curious, as there are a ton of threads on here about gearing.
everyone tells me that the 3.31 is not the best for towing. With the trailer loaded its close to 8000#
Everyone who's telling you that hasn't driven a truck with the 6R80 transmission. Going from 3.31 to 3.73 will only gain ~12% more torque in any given gear. Do you really think 12% is worth the expense? I sure wouldn't.
If your engine gets too hot your truck will reduce power; if this happens frequently while towing then I would recommend getting the upgraded radiator. If not I wouldn't bother.
You will be close to the max recommended for your gearing, but changing to 3.73's only gets you another 1400 lbs or so ... as Tom said above, there's not a lot of gain from going from one gear set to the other.
i'd give it a try before you dump a grand into a gear change, you may not feel the need.
Just be realistic.... it is going to shift, and it is going to "feel" heavy. but let the trans do it's thing and use the skinny pedal to decide how fast you want to go, and how quickly you want to get up to speed. Changing to 3.73's isn't likely going to make it shift a whole lot less, to be honest.