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Rust Prevention on undercarriage

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2015 2500 HD with 137k miles already. I am the second owner and plan on keeping this truck for a very long time. What can I do now to help slow down or prevent rust. Iowa winters (salt, sand, and the liquid salt) are rough on frames.


Fluid film?

Take truck to a shop and let them undercoat the bottom?

Other options?


I try to wash the truck when the temperature is reasonable here.

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The trick with the wax GM uses, is oils will soften the crap out of the wax, and it will wipe right off the frame. I would touch up the wax with Daubert nox rust B121, which is the coating GM uses on the frames, or have it done while you are under warranty from the dealer. As for sheetmetal, Fluid Film or Boeshield T9.

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Fluid film killed my frame coating. Armor all works well on my 2003 frame coating.


You need to spend more time on the main areas, but take this from a Southerner who sees salt about twice a decade.


You could hit every fastener you see with a penetrating oil. And for most fasteners you remove- reinstall with anti seize.


For the black painted metal, I find fresh motor oil makes them look great. You could use a paint brush- I use shop towels or microfibers that are near death.


Get a comfortable creeper, some quality wrap around safety glasses and set your supplies beside the truck and you can get alot done. I would do this twice a year- once before winter hits and once after no more salt is on the road.


You need to hit your brake lines. I dont know what is best for them, but I figure anything is ok- whether it be armor all, motor oil or brake fluid.


When you are under your truck, you can take instant detailer, waterless wash or whatever and wash the insides of the body panels so they do not rust. Pay attention to the cab corners.


Wd-40, penetrating fluid, or kerosene can be used on the exhaust system. Be careful as to not start a fire- but a good wipedown of the headers/manifold to the cats to the mufflers to the exhaust tips may be beneficial for you.


Don't forget under the hood. I have seen beautiful cars on ebay that are trashed in the engine bay. Motor oil, penetrant, electrical cleaner, silicone grease, armor all, soapy towels can do wonders with some time and a gentle hand under the hood. Take care of your wiring and grounds, ignition system, fusing panel, radiator, brake lines and brake cylinder, battery case and posts/terminals, the paint under the hood and on the firewall, armor all radiator hoses, a dab of silicone grease on both sides of your belt.......... Try not to have a ham-fisted manhandling grip- some parts are sensitive and can break- but you may be in luck since your truck is new. Sometimes, on old cars the heat can eventually cause plastics and stuff to become brittle and snap easily.



Grease or oil your door latches, handles, strikers. On the tailgate get oil on the locks, inside the handle, on the cables. Hood latch needs oil too. Wash and wax all paint- door jambs, clean the bed the best you can. Polish chrome. Use the good stuff on your windows inside and out and the windshield. Dont forget the antenna.





Grease your suspension fittings. Wipe the boots down real well without being rough enough to damage them. Upper and lower arms could be oiled with a soaked cloth. The backing for disc brakes could be too. Dont neglect where the brake hose meets the caliper, nor the bleeder screw. Wipe the calipers clean. Detail the inside of the wheels. Put anti seize on your lugs (but reduce torque upon reinstall) and the mount faces so they dont get stuck. Clean your spare tire's tread, both sidewalls and both wheel sides. Check psi. Check and oil the apparatus used to secure and move the spare tire. Wipe down shock absorbers with armor all, soapy water or motor oil on a rag.





Clean fuel tank and its mounting structure. Oil with something. Carefully inspect and cleanse fuel lines and connections, fuel filter, etc


Wipe your axle down with a gear oil soaked rag- or whatever you have that wont be harmful to anything. Wpe the pumpkin and all the bolts securing the cover to it. A shot of penetrant on each bolt is a good idea to me. Inspect and clean your hitch and hitch mounting fasteners and hardware.






Mud can gather inside of bumpers, on the inner part of sheetmetal and other places. It can be troublesome and accelerate rust and corrosion. Lube your door pivots so they are protected from rusting, open and close more smoothly, and function properly. Silicone grease and/or armor all on all rubber and weatherstripping.


Clean your wiper arms. Oil the pivots. Clean the blades with concentrated washer fluid.







Oil your driveshaft. This is one of the last things I did. It was dry and had a patina to it after probably 13 years. I think I used a soft cloth with good motor oil and wiped every inch of it and it soaked up the oil quite well. Dont forget the ujoints and anyother exposed metal parts.




If you can touch it, use a cloth. If not use a spray but be careful that the overspray will not destroy or degrade nearby materials or components.





Bottom line, there is alot to this. Many many parts under the truck. The sooner you start, it should be easier and you can do a little here and some there. I got my truck two years ago with 160,xxx miles. It was an 03 so it was 12 years old. It seems everytime I look at it I find some part that could use attention. But then again, I want my Grandson to give this truck to his Grandson.

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