So I am talking to my brother about how great my 2016 (3.5 Ecoboost) tows my 24 ft boat and he asks for max capacity......I read the door sticker which has not only "L9" but a code of "52". I know the first means rear locker - I thought 3.73, BUT the RC52 is the 4.10 right?

 

L9 is 3.55 gearing with a locking diff'

Identify Your Ford Truck Axle From The Door Sticker – Blue Oval Trucks

Most of the trucks I see with the 3.5 have 3.31 gears. The ones intended for towing have 3.55's

They put a few 3.73's in the early years of the 3.5, but I haven't seen one newer than about 2012 with 3.73's. They may have made a few after that, but I've not seen one.

 

That makes sense but then what does the code "52" mean?

 

Found the window sticker confirming your call on the 3.55 e locker. Tow package so 11100 is high end tow load. Still can't figure out the "52" code on the door sticker.

 

Where on the door sticker is the 52 located? Is right next to the L9 code in the Axle box or elsewhere?

 

here is the sticker....what does the 52 mean??

 

Being that 52 is above that line, it looks like it wouldn’t have anything to do with the axle.

 

I have been looking and I think it is a radio code or some type of region code...

 

Correct, Region Code. This explains the sticker
https://www.blueovaltech.com/tech/decode.php

 

I have a 2023 XL with the heavy-duty payload package, and it has both the 3.5L EcoBoost and 3.73 gears. The 3.73 gears were standard with the HDPP.

But it looks like the HDPP has been discontinued for 2024, so that combination may no longer be an option.