Rust

[epa1775]

So after completing my first winter in Utah the undercarriage of my truck now has rust. I've purchased two different products. I've thought about using the spray on bedliner stuff that comes in a can or some Rust B Gone stuff that comes in can. I'd really like to take care of the stuff on the frame. Or should I be concerned about the rust at all?

Thanks for the help.

Pete

[More Power]

These frames are normally coated at the factory with a black undercoating type material. Generally, this works well to keep the frame from rusting. However, the disc rotors, steel driveline components, front spindles, CV axles, and some other front suspension components arrive at your dealership as bare steel (partially) and without any rust protection.

From a truck owner's perspective, the best time to stop the rust is when the truck is brand new. A little black paint can help.

Here's part of an editorial I wrote four years ago about this problem....

Room for Improvement
What enthusiasts would like to see...

A certain segment of the Duramax powered 2500HD/3500 truck buying group is comprised of enthusiasts - those who obsess to some degree over the look, ride, utility or performance of their new truck. Including myself as part of that group, I've winced at certain details of the new trucks. GM could easily rectify the situation, and this article is intended to highlight some of what I feel needs attention.

The arrival of GM's Duramax 6600 came after about a year and a half of intense pre-release publicity - including extensive coverage right here in The Diesel Page. Publicity photos released by GM in mid 2000 showed how much aluminum was incorporated and how nice the engine appeared. Those early photos showed that the first prototype engines were built using, at least some, anodized aluminum components. They were great photos, but we all know the production engines departed from those photos by not incorporating anodized aluminum components or protective coatings of any kind.

While pretty when new, the luster of all that bright raw aluminum soon dulls with the accumulation of surface corrosion. Enthusiasts keep their engine compartments clean, but no amount of powerwashing or attention to detail can keep the aluminum components from turning first light gray then form a powdery aluminum oxide coating. Those who live near coastal areas or are exposed to road de-icer in the winter will see their bright and shiny aluminum turn toward the dark side all the sooner.



The cast iron Duramax engine blocks arrive from Germany in painted form, but the final machining is performed at the DMAX plant in Ohio. All of the engine mount bosses, timing cover flange, indeed all other areas of the block are machined after the block was originally painted.

The engine shown here was only a few months old when the photo was taken, but the raw cast iron machined areas (not covered by other engine components) have already begun accumulating a patina of rust. For an enthusiastic owner, there is nothing you can do, short of spraying a messy rust preventive every few weeks onto all of the exposed areas.

The solution for the oxidizing aluminum and rusting cast iron would be to spray a clear coating onto the assembled engine while still on the production line. Motorcycle manufacturers learned back in the sixties that owners rejected oxidized aluminum and demanded their shiny new motorcycle maintain its brightwork throughout its useful life. All of the motorcycle manufacturers stepped up to the plate and began coating all of their engines and other aluminum components with a durable clear finish. Certainly, the engine coating technology exists today to maintain the appearance of the Duramax.

One of our members (who is an enthusiast) worked with a custom engine builder a couple of years ago to build a custom 6.5L diesel engine for his truck. Part of the buildup included ceramic coating the cast iron exhaust manifolds, which mimics aluminum in its appearance. Even after more than two years of use, those exhaust manifolds are still bright and shiny. Indeed, ceramic coatings work very well to maintain a custom appearance for items like cast iron exhaust manifolds. Relatively small details like these would add value to the truck and build brand loyalty, both when new and on the secondary market - for many years to come.



This photo shows a CV shaft on a brand new Chevy 3500 SRW 4x4 that the owner had not yet taken delivery of. In fact, a local Chevy dealership delivered this truck directly to a custom truck shop to get a suspension lift, big tires and a host of other custom touches before the owner took possession.

Unfortunately, the CV shaft had already begun rusting. On a lifted truck, the ugliness of the rust is all the more apparent, and is so preventable. Indeed, if you look under any new GM truck, you'll see rusting drivelines, suspension components, brake rotors, and other appearance issues that are so unnecessary. Many of the aftermarket brake rotor suppliers offer cadmium coated rotors - primarily because they know they are dealing with enthusiasts who value appearance.

Now, before getting too carried away, you should know that I still feel these are great trucks, and that what has been mentioned here are simply cosmetic issues I feel need attention. Perhaps GM will one day offer coated engine and drivetrain components, and bigger tires. Considering what these trucks cost, I don't think that's too much to ask. TDP

Jim

[cowboywildbill]

First thing I did was paint all of the shafts and bare metal. I painted it again in a couple of days. You always seem to miss a few spots the first time and a second coat helps. Rotating the driveshafts and joints while I sprayed helped get all of it. I even paint the backing plates and all bare parts but taking care not to get the rotors and pads coated. What a difference it makes a year later when your under there looking around.

[jbplock]

First thing I did was paint all of the shafts and bare metal. I painted it again in a couple of days. You always seem to miss a few spots the first time and a second coat helps. Rotating the driveshafts and joints while I sprayed helped get all of it. I even paint the backing plates and all bare parts but taking care not to get the rotors and pads coated. What a difference it makes a year later when your under there looking around.

Good idea! .. I coated mine with AMSOIL HD Metal protector (cosmoline) but after nearly 6 years it's due for another treatment .. I've thought about using some POR-15..

Regarding brake rotors, I've heard of guys masking the surface of new rotor and painting with high heat paint.. I haven't tried it but seems like it would keep the inside vent area of the rotor form rusting and scaling.

[Turbo Al]

Well I bought my 2001 new and it pretty much stayed in my driveway for the first two weeks mostly because the interior and the front end were taken off of it! It was summer so very hot I removed the interior and painted all the metal floor boards with a rubber undercoating. Then I took the front end apart and undercoated everything I possibly could. Also did the inner fenders, frame, rocker panels, under the box, etc. Where I couldn't spray the undercoat I used a paint brush.

Al