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Chevy Silverado and GMC Sierra Undercarriage Rust

I purchased a 2008 GMC Sierra this weekend and after I got it home I noticed that the undercarriage had quite a few areas with surface rust. The rearend housing also has a bit of rust and the backs of the front spindles are rusted. It is all just surface rust, but it still kind of bothers me. I took the truck in to get detailed at the GMC dealer today and asked about the rust. They said that there was a technical service bulletin for this issue and proceeded to spray a little flat black paint of areas that are easily seen. I guess they thought that I would look under the truck. I would prefer something a little more factory like the rubberized black paint normally used on the undercarriage.

Are areas of surface rust on the undercarriage normal on a new truck? Should I even worry about it? Lastly, what if anything does the dealer have to do for a technical service bulletin?

Thanks in advance.
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Comments

  • obyoneobyone Posts: 8,065
    A TSB is information regarding procedures or changes in procedures for repair or parts. Basically it is a way for the factory to communicate changes to the dealer whether it be tools, service procedures, upgraded parts, etc.

    If there was a tsb regarding surface rust, I ASSURE you that spraying flat black paint on unprepped surface rust IS NOT part of any TSB. There are sites like alldatadiy.com where you can get a detailed list of the TSBs available for your truck. The manufacturers really don't like you doing this as you may find problems with your truck that you never really noticed in the past but because of a description in the TSB suddenly you need to make a warranty service appointment.
  • bensierrabensierra Posts: 2
    My dad purchased a 2008 Sierra 2500 HD last year and asked me to rustproof the frame last fall. I went to my local NAPA store and bought a 5 gal.Rustproofing Undercoat...can remember the brand but I'll check. We put it on the hoist and I noticed the same thing as you. Control arms and rear end were starting to rust. I undercoated the complete frame in and out without any misses. I used about half the pail. I also did doors, rockers, box sides etc....Here's were it gets interesting, 2 months down the road he stopped at the local carwash to clean the winter salt of the truck. The factory undercoating was peeling off like you wouldn't believe!!! The rustproofing totally destroyed the SOFT, STICKY factory undercoating. We are currently trying to clean that stuff off. Never seen anything this hard to clean in my 12 years of Auto Body Repair. Pressure wash, degreased, scrape off, wire brush, degrease again, pressure wash and finally sand blast to finish it all off before epoxy/paint. Nightmare!!!! Wondering if anyone else had or heard of this happening to someone??
  • ntsmith69ntsmith69 Posts: 5
    i am in autobody as well. and what i found that exp on frames and the under carrage is to clean it as best as you can. then use rust converter on the whole area thats needs to be painted. after that dries spay an etch primer on it. you can buy this in cans called ONE STEP self etching primer. this will help bond the new paint to the frame. i have done this to many vehicles and never had a problem. even on the factory coating just add the etch primer and you should not have a problem. it is all in cans so no need of spray guns. and for the top coating i use rock guard in cans. the paintble type . i found the other ones do not harden as much and if you want to touch it up down the road it is easier. but spraying black paint over it will just come off and is just for looks till you get out of the garage.
  • bensierrabensierra Posts: 2
    The thing is that rust converter needs rust to work. When you peeled the soft coating off where it hadn't peel yet, the frame was clean bare steel. The rust proofing had melted the factory even softer than it was.Check the new generation GM and no paint or primer will stick on that frame undercoating. You can't blast it or sand it. Stick your fingernail in it and you'll scrape it down to bare metal. It's almost like a grease.
  • looking at my frame last weekend i noticed the wax peeling off rusting members from stem to stern.

    warranty service doesn't seem like a likely option - any ideas?

    (nbs1500wt, 2008)
  • mram50mram50 Posts: 5
    Rust doesn't go away..it just keeps creeping in, but on the frame, unless you live in a high road salt area it shouldn't be a major problem, but if it gets real bad you might consider sand blasting it, painting to cover the pitting or if its REAL bad welding some new steel in there, but frames are generally pretty darn strong and can withstand quite a bit of rust..
    Sorry about the extra post I had to delete.. I'm new here..just trying to figure out how the boards work.
  • Hi,

    I am currently suing GM right now for this very problem. I live in coastal FL and have extensive corrosion throught the undercarriage. GM refused to cover under the warranty because they say it was caused by the environment. Of course it was. All corrosion is caused by the environment.

    FYI. I have deposed the senior GM manager from Michigan who developed the coating spec for the undercarriage wax coating. He says it was only designed to last and protect the vehicle for a year in the most hostile environments (the 95th percentile as they call it), and that GM fully expects the coating to fail and the vehicle to begin corroding after a year.

    GM added an exclusion for corrosion due to sea air and road salt in the 2007 warranty. I have a 2005, which does not have this exclusion (they clearly added it because they knew their vehicles were vulnerable). Yet they still will not cover it, claiming that there is an exclusion for airborne fallout (they consider salt in the air and even water in the air to be airborne fallout, though it does not say this in the warranty).

    The warranty is a sham and I believe I will win in court two weeks from now.

    Can you give me more info about your vehicle. My action may help you.
  • I am suing GM for this right now. Case goes to court in two weeks.

    I have a 2005 Silverado 2500 and the entire undercarriage is corroded. Started to get bad after about a year. I live in coastal FL.

    I have deposed the GM corrosion engineer who developed the spec for the wax undercoating. GM does not apply this coat. It's suppliers do, and some parts are uncoated. He says its for cosmetic protection only and only designed to last a year in the worst environments (GM designs its coating for what it calls the 95th percentile of environments). After that, GM expects the coating to flake off and the vehicle to corrode.

    GM refuses to cover undercarriage corrosion because they say it was caused by the environment. Duh. All corrosion is caused by the environment.

    GM also says that their bumper to bumper warranty doesn't cover undercarriage corrosion, only sheet metal. This is not true. The bumper to bumper warranty covers everything except that which is not specially excluded, and there is no exclusion for the undercarriage. There is an exclsuion for corosion caused by airborne fallout, but GM is claiming that salt and even rain count as airborne fallout.

    Note that GM added a further exclusion for sea air and road salt to its 2007 warranty. It shows they know their vulnerability.

    GM should repair your vehicle or give you a new one under the warranty, but they won't. That business with the black paint is nonsense. The dealer made it up. Either that or GM has really stepped in it.

    Can you get me the number of that TSP.

    Also, can you tell me where you live? State and proximity to salt water. Do they use road salt. What is the extent of the corrosion.

    You may be able to get relief based on the outcome of my case. I'm thinking it might even develop into a class action.

    I believe GM is misleading the public about its corrosion vulnerabilty and warranty.
  • I have a 2005 Silverado 2500 and the entire undercarriage is corroded. Started to get bad after about a year. I live in coastal FL.

    I am suing GM for this right now. Case goes to court in two weeks.

    I have deposed the GM corrosion engineer who developed the spec for the wax undercoating. GM does not apply this coat. It's suppliers do, and some parts are uncoated. He says its for cosmetic protection only and only designed to last a year in the worst environments (GM designs its coating for what it calls the 95th percentile of environments). After that, GM expects the coating to flake off and the vehicle to corrode.

    GM refuses to cover undercarriage corrosion because they say it was caused by the environment. Duh. All corrosion is caused by the environment.

    GM also says that their bumper to bumper warranty doesn't cover undercarriage corrosion, only sheet metal. This is not true. The bumper to bumper warranty covers everything except that which is not specially excluded, and there is no exclusion for the undercarriage. There is an exclsuion for corosion caused by airborne fallout, but GM is claiming that salt and even rain count as airborne fallout.

    Note that GM added a further exclusion for sea air and road salt to its 2007 warranty. It shows they know their vulnerability.

    I believe GM is misleading the public about its corrosion vulnerabilty and warranty.

    Let me know if you are having corrosion problems with your GM vehicle. Together, we can hold GM accountable.
  • I have a nbs1500wt 2007 model year. Took it to the dealer, they photographed it and said they would send it into GM > that was months ago and I have yet to get a reply.

    :cry:
  • Silly in the extreme isn't it?
    I worked as a body repair person for quite some time and one was a slap it together joint where we "fixed" vehicles being sold, resold and resold again by used car lots. Many were GM models full of rust and quite often BIG rust holes were covered with fiberglass and nothing more..the first big bump and your car suddenly has a gaping hole in it.
    While this is not the same as a new vehicle it just shows that the auto industry in their zeal to sell more and more new cars and trucks build them to last as short a period as possible. Remember, GM invented "planned obsolescence" with the infamous Corvaire. Don't let them forget that period of GM's history in court. It appears that they have changed nothing and it's why GM needed a massive bailout..again.
  • They did the same with mine. Sent photos to GM area rep, who rejected the claim a couple of weeks later. You should have heard back by now.

    The GM corrosion expert I deposed said that widespread corrosion under the vehicle would not be covered anywhere in the U.S., even in a desert.

    How extensive is the corrosion. Where are you located? Have you used the vehicle off road. Do you garage it, wash it, etc.
  • "How extensive is the corrosion. Where are you located? Have you used the vehicle off road. Do you garage it, wash it, etc."

    how does one measure corrosion? wax has pealed off every inch of the frame revealing a rust colored surface

    chicago area, never off road, but municipal road crews use salt in the winter
  • arp2arp2 Posts: 1
    has your case gone to court yet?
  • My corrosion is extensive. All undercarriage components. Significant metal degration in some areas. Started like yours I think. After a few months I began to see cosmetic corrosion throughout frame, progressing to more structural corrosion. Brakes crumbled, power steering coolant tank rusted through, suspension componets nearing failure.

    I am in Melbourne Beach, FL. Never been off road, but am near beach, with high salt and humidity.

    Have you followed up with the dealer tosee GM's opinion. Email me at kmarrin@davismarrin.com to discuss further. I might be able to help you.
  • Was supposed to go this week. Postponed till next week or the week after depending on completion of another case on the docket.

    What is your situation?
  • missritamissrita Posts: 1
    I would be very interested in your outcome . I own a 2004 Chevy Silverado 2500HD with the whole undercarriage rusted, I bouught this truck used from a dealership 2 years ago and the undercarriage was black, I started noticing the rust about a year ago. If this is something that cant be fixed, I would be very interested in a class action suit. My email is ritaseay@msn.com.
  • zap73zap73 Posts: 1
    I was just told by my mechanic I need ALL new rotors, calipers, pads etc. My 2005 Silverado 2500HD with 19,500 (yes original miles) The rotors are rotted so bad that the pads are only contacting the rotor surface to stop the truck by less then 25 %. I was wondering why it was hard to stop the truck at times. Well the inside rotors are corroded so bad that the pad contact is 1/2 inch.... scary.... I sent GM a email then looked at this post. I Guess I should just go trade it in on a FORD.....Oh the reason he had it on trhe rack was to replace the a/c compressor that blew with less then 20 k on the clock. I know the truck is almost 5 years old but comeone....It was 41K brand new.......
  • Silverado Rust Bucket,

    I am suing GM right now for undercarriage corrosion. I have also filed a complaint with NHTSB.

    My brake rotors were taken out in pieces when the vehicle was two years old, and they are toast again now at 29,000 miles.

    Do you have other corrosion issues on the undercarriage, or just the rotors.

    I have deposed the GM expert from Detroit who designed the undercarriage corrosion protection. I have lots of good info if you are interested.

    Please email me at kmarrin@davismarrin.com
  • How is your truck doing now?

    I am suing GM for undercarriage corrosion right now.

    My email is kmarrin@davismarrin.com
  • Rust proofing voids the warranty.

    How is your truck doing now?

    I am in a lawsuit with GM for undercarriage corrosion and have deposed the GM corrosion expert from Detroit.

    He says that their wax undercoating protection is designed to last only one year and that many components aren't protected at all.

    My amil is kmarrin@davismarrin.com.
  • How is your truck doing?

    I am still in court with GM now on my undercarriage corrosion.

    My email is kmarrin@davismarrin.com
  • KCRamKCRam Mt. Arlington NJPosts: 3,516
    ...please do NOT put your email address in your messages. If you wish to have off-list email contact, go to the Forums Preferences selection in the right-hand menu, and make your email address "public" (scroll to the email settings section and follow the link and instructions). This will make your email address visible to other members when someone clicks on your username.

    kcram - Pickups/Wagons Host
  • gmcustsvcgmcustsvc Posts: 4,064
    Hello zap73,
    I apologize that you have had concerns with your vehicle. Can you please email me at socialmedia@gm.com so I can look into your situation further? Thank you,
    Mariah GM Customer Service
  • I just found that my upper shock bracket on the passenger side blew right through the frame brace where it mounts due to major rust and rot My truck is A 2000 silverado 1500 but come on GM it looks like my truck sat on a beach for 2 years straight wich it has not the under carriage is so bad. Already lost brake lines due to rust issues and my rocker panels are starting to fall apart to. I was very excited when I got my silverado but now not so much
  • kendonhankkendonhank Posts: 61
    Has GM done anything for you?

    I am in court with them right now on my undercarriage corrosion.

    2005 Silverado HD with 2500 miles.

    Have you filed a comlaint with NHTSB. They are doing an ivestigation on brake lines right now.
  • kendonhankkendonhank Posts: 61
    When did you first notice major undercarriage corrosion.

    Where do you live and do you garage the vehicle.

    Do you have any photos?
  • You are kidding right? class action suit for undercarriage rust on a 6 year old truck! For about 7 bucks a can you can buy 3M rubberized undercoating, it takes about 3 cans to do under the box and 2 for under cab... It's a truck and the undercoating gets beat up and needs to be recoated from time to time. If you don't recoat the undercarraige at least once every couple years, you will get rust as a result of your neglect... ;)
  • kendonhankkendonhank Posts: 61
    No, she's not kidding. My truck was rusted out underneath in less than two years.

    And undercoating voids the warranty.

    I have looked at hundreds of vehicles in my area that are left outside 24 x 7, have never been undercoated, and have never been washed, and the undercarriages are in perfect condition.

    The trucks that are rusting prematurely have inadequate protection from the factory.
  • No I have not contacted any one figured my truck was to old to have any support from GM. I have had the truck about 4 years bought it used and to be honest did not notice how bad it was under their till I lost 2 brake lines within a couple months it's so far gone that I think I'm going to just get rid of it. I live in RI where there is lots of road salt in the winter so that made the problem 10 times worse I'm sure. But I see it is a common problem now so might not buy a chevy this time. I will get some pics and put them up just for people to look at
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