I know we have talked about it before, but I still don't get it. Look under your car and you will find 99% of the time surface
rust starting to appear on your driveshaft and other parts under there. Looking on the Ford Racing Performance Parts page, I see where
they pretty much accept the fact parts rust and has even given a reason for it.
This is what it says;

409 stainless has excellent forming characteristics and is rust through resistant.
A surface rust will form in most instances. This rust retards further corrosion.

RIGHT!

 

The rust is not just acceptable but wanted. If we had parts under there that were coated then we would have issues, but yes the surface rust does protect from further rust happening. You will get a coating but no more than that. The only stuff that should have a coating of rust would be the driveshaft and the rear, everything else is coated in one way or another. Don't sweat the small stuff all is right down below...

 

every driveshaft I have ever seen has surface rust, unless it is aluminum. Surface rust is normal and prevents further rust, don't sweat it one bit.

 

I know where there is a brand new bridge that was never painted. Just allowed to rust, for the very reason that you were talking about. Gun bluing is a form of rust that is used to protect metal.
Hey, maybe they should come out with blued driveshafts? Hmmm...cool mod.

 

Yeah the surface rust prevents further rusting I agree, that's one reason why it isn't coated. However it's also not coated because it is cheaper to not coat it and just allow it to surface rust. There are people on this forum who have purchased a brand new Mustang, took it home, took all the parts that'll rust out of the rear end of the car, painted it (probably black) and bolted it all back in. That's a lot of work but can bring peace of mind. I just went under there and painted what I could without taking it apart, but you have to be careful to not get any paint on anything that moves or is some sort of seal.

 

A friend just bought an '07 GT. He is going to put some type of under coating after he wire brushes all the surface rust off.

I guess when you think about it, it does make sense, but it sure looks ugly.

 

yeh every car pretty much does that...as long as its on the surface its not affecting anything negatively, and it should not ever rust to the point of where it eats through the metal

 

But noone sees the driveshaft so why does it matter? I'm as **** as the next guy, but that is past even my limits. Also why mess with taking it off and painting it, possibility of dropping or getting it out of balance? Anyways best of luck to him.

 

I know....you guys are right, leave well enough alone.

 

Dont undercoat that driveshaft as it will unbalance it and it will self destruct at high speeds. [:@]
Aluminum corrodes but the corrosion that forms keeps it from further corroding. Think
of that one next time you fly in an aluminum airplane.
Read up on themercury paste the UStroops used during the world wars.