Seems excessive to me unless you're driving on salted roads..

 

My 2011 was like that from the lot. It had surface rust on the entire front cast iron portion of the rear diff housing, several areas of the rear axle housing that were unpainted, leaf spring keepers, and rear body mount cartridges. My driveshaft is aluminum, so that wasn't like yours. It appeared there was ZERO paint on the cast rear diff housing from the factory. Obviously with no paint, one would expect the surface to rust over very quickly. I think that has changed from 2010 and before, because I went to a few dealers after seeing mine, to look at some used F150's, and the '10's and older looked to have paint on them, and not nearly as ugly as my brand new one.

Worth mentioning, though, is that the surface rust will never be an issue for the rear diff housing, and is merely a cosmetic issue. I didn't like it either, and sprayed all the rusty spots with black rust reformer paint right before I took it to the dealer for undercoating (which didn't get done on any of the suspension parts anyway?).

Also, on new vehicles, when that new metal rusts, it is really noticeable, since it is a bright orange color on clean metal. Once the surface ages a bit, the rust evens out in appearance, and turns a less noticeable brown. I recall this from having new dirt bikes, and the brake discs rust in the vent holes a very bright and ugly orange. Then, after some time, all those little holes get covered with a more muted and dull brown "finish" of rust, and it doesn't look as bad.

I do wish Ford would simply paint the darn rear axle assembly, though...nobody wants to look under their brand new truck and see that!

 

This is %100 normal. Just get under there with some rust paint and problem solved.

 

[QUOTE="Jimbo45"] My driveshaft is aluminum, so that wasn't like yours.[QUOTE]

 

Crap, I don't know how I screwed up that last quote!!!?? I meant to say, I tought all the newer driveshafts were aluminum??

 

To the original OP. You will get multiple responses on here from wether it is ok to have rust or not. It has been discussed many times on this forum. I bought a 2011 Platinum and it looked like a 20 yr old truck underneath. I actually went to arbitration with Ford on this very issue, the below link will take you to some of the discussion and responses that I posted from Ford. See the later pages of this discussion.

https://www.f150forum.com/f38/2011-l...-87176/index8/

Now, dont get me wrong, it is a great truck, and I do love it, but there is some accountablility on a manufacture to do the right thing. My main problem with the whole thing was they openly admitted they paint some and dont others. That was my main beef, because they certainly dont charge those that are unpainted any less.

Regards
JR

 

Dunno if it's already been said bc in too lazy to read the other posts. But someone on here had a similar problem and they said it was rail rust.

 

That was a different issue, and it is called Rail Dust.

That is a form of environmental 'fallout' on the exterior (mostly the horizontal) painted surfaces of a vehicle, found more commonly in cities where there is a lot of heavy industry and/or rail traffic, wherein the material produced by trains running over metal rails, sends iron oxide and other particulate matter into the atmosphere, where it comes back down and settles on painted surfaces, and over time, can create a chemical reaction which can damage the paint, if not cleaned off.

Most of my vehicles, have had the type of rust which the OP is commenting on, either on the rear diff' or the driveshaft, right from the start. BTW, it has nothing to do with "cheap steel from China" as another member stated; bare steel rusts--no matter what the origin.

 

I just want to compliment you on your awesome rail dust explanation...sounded textbook!!

 

Thanks, in addition to my long-time primary career path, I had for many years, an auto detailing business on the side; and several years ago this was all explained to me in a tech-class I took, which was put on by one of the major detailing gurus in SoCal, the car capital of the world!