- sounds like you requirements changed after purchase?
I am in-the-same-boat as you in terms of initial towing requirements = I have a 7x16 enclosed trailer for moving my tractors around.
You have the same trim levels as I do in my 2018 Platinum FX4. While Ford offers a bunch of F150 axle "choices" (and I use that term sarcastically), you really don't have a choice based on the Platinum Trim level and the addition of the FX4 package.
I summarized a lot of this in the Axle and Frame Research
thread (read all the posts) and just by picking the 3.0L V6 Diesel engine, you limit your axle choices right out-of-the-gate to:
- X27 Non-Limited-Slip 3.31
- XL3 Electronic-Locking 3.31
- XL9 Electronic-Locking 3.55
and once you check the box for the FX4 package, you are "locked in" (pun intended) to the XL3 Electronic 3.31.
My assumption is that if you ordered the FX4 package for off-roading, they stuck the shortest ratio axle in for maximizing off-road rocking climbing potential. This contradicts why they only offer longest (4.10) axle option (which would be great for towing) in the Raptor, unless they assume all Raptor owners are doing Baja-style long distance desert racing.
I don't know what it would cost to swap out a different axle assembly, but my guess is that it wouldn't be worth it.
Since this is pretty much water-over-the-bridge, what you got is what you got, but I thought I'd explain from my previous research of the F150 Ordering Guide how you arrived at the axle you got.