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I'm the second owner of my 2014 GX 460. I bought it in winter 2019.
I thought of rust proofing the underside as much as possible to help with the harsh Canadian winters. I found the usual rust on the weld seams, which I treated and will paint soon. But almost all the skid plates or "belly pans" were in sorry state. Part being because the factory black paint is not as sturdy as I hoped it would.
I took them all out, washed and cleaned. There are 3 big plates: One under the engine (has a mesh on the front), one under the oil pan/transmission and another under the fuel tank. An application of rust converter followed by POR15 or bedliner should take care of it. I will also shoot rust proofing spray inside the frame rails and any cavities.
But then, I found some mud and gravel stuck under the protective covers on the KDSS accumulator. I removed the covers to see reveal a horror story underneath! It looks like mud got stuck there and caused galvanic corrosion between the accumulator body (Aluminum) and surrounding steel. The accumulator is hardly recognizable with all that rust around it. I chipped as much as possible and will spray it with some rust inhibitor to stop further rusting.
I believe the truck may have been stuck in mud on this side only since the rest of it is clear and doesn't have any encased mud anywhere else. I'm probably lucky in this regard otherwise I would have been cleaning mud for days..
I thought of sharing the info with you so whoever lives or drives in the salt belt to check these areas for rust and corrosion..
KDSS Protective cover KDSS Accumulator (where is it?) Fuel Tank skid plate Rust converter applied (before drying)
Last edited by cancruiser; Sep 9, 2021 at 10:31 AM.
Yup, that's a nightmare. Sounds like your giving your GX some much needed TLC!
Replacing the KDSS accumulator will not be cheap and operating it is required to properly install any future suspension components so I hope for your sake, you don't need to touch the KDSS at all for any reason because I doubt by the looks of it, it works. Once you get that all cleaned up lather it with as much fluid film or woolwax as you can.... antiseize all your skid plate bolts as well so they're easy to remove after future winters.
My KDSS cover was packed full of mud and gravel as well, on a truck I fully believe had never been offroad prior to purchase last year. Cleaned it out and fluid filmed it up, fingers crossed future me appreciates the effort, lol.
Can a product like fluid film be applied to the accumulator to prevent this from happening?
I suppose so. All you need is to prevent galvanic corrosion in this case. Fluid film is a good product but it can wash off. But in this area, since it is covered, I would say it should work fine.
In my GX, I used CRC corrosion inhibitor, which is basically a cavity wax, so it doesn't wash off easily. Also, because I ran out of Fluid Film
I actually applied Fluid Film this past weekend to the entire frame, skid plates and the KDSS accumulator. I had reservations about doing this on a 2021 GX but this thread and other postings online incentivized me to move forward with it. I also didn't want a repeat of having a frame replaced which was the case with my Tacoma. The Tacoma sat for over a 6 months which resulted in the brakes rusting and costing me $500 to replace them (dealer didn't help with the cost ). To make things easier, I picked up the
off Amazon. In addition, I let the 1 gallon sit in the sun (ambient temp was about 75 degrees that day) for a few hours which aided in making it more liquid like and therefore easier to spray/manage. It still took me about 8 hours on a Saturday to complete the project since I removed the wheels (including the spare), skid plates and covered the brakes/rotors before spraying. I did it all in my garage but in all honestly not sure I'll do it again under those conditions since crawling around on a concrete floor isn't exactly my idea of fun at my age. I'm convinced a lift is needed since you can stand, have better sight lines and better angles which would certainly have sped things up. Overall, I'm happy with the results and hope it provides at least a couple years of protection since I don't plan on repeating it every year. On a side note, a lot complain about the smell but initially it didn't seem that bad after opening the can and taking a big whiff. However, I fully understand after spraying/smelling it for 1/2 a day. It really smells like a farm and is very noticeable for the first few days after getting the vehicle up to operating temperature where is burns off any on the exhaust/lower engine. Although, I'm not certain you could prevent all overspray on the exhaust unless you covered the entire run which is just too time consuming given the size of the project already.
The wife wasn't thrilled I stunk up the garage so the GX has been parked outside all week but is essentially smell & drip free now. I would also advise of removing any other vehicles you have in your garage if you intend to spray under those conditions as it sticks to everything once it's air borne. As you can imagine, I had to wash the entire Lexus and garage flooring after applying the Fluid Film treatment but it comes off really easy which is a good thing. Anyhow, if there's any questions let me know but there are plenty of videos showing how it's applied including follow-ups to how well it holds up. In addition, it would be great if there was anyone in the South Central Pennsylvania area with a 4 post lift and wouldn't mind allowing use of said lift on the next go-around of Fluid Film. I'd being willing to rent the lift at a reasonable rate just to avoid crawling around on a concrete floor again. I realize that's a long shot but figured it couldn't hurt to see if there's options out there.
Fluid Film is really really great stuff. I've used it for years on various vehicles with great results. I also like WD40 believe it or not. I find it surprisingly good. This may be more than some would do but this is what I do. When I get a different vehicle new to me, like the latest 2011 GX 460, I will coat the entire undercarrage with WD40 drive it for a while couple weeks. Then I pressure wash it off, it cleans it so well, better than any soap I've used. I have 4 ramps I put the vehicle up on then I coat the undercarriage with Fluid Film. Our Jeep, after we take an off road trip and the bottom is nasty, I pressure wash it, and WD it and let it sit pressure wash it again and it looks brand new. I keep Fluid Film on the Jeep as well. I've never used Fluid Film on our 2015 F150 just WD40 the frame and everything under it looks fantastic. I'm doing a test on it. We have had it since new.
I'm the second owner of my 2014 GX 460. I bought it in winter 2019.
I thought of rust proofing the underside as much as possible to help with the harsh Canadian winters. I found the usual rust on the weld seams, which I treated and will paint soon. But almost all the skid plates or "belly pans" were in sorry state. Part being because the factory black paint is not as sturdy as I hoped it would.
I took them all out, washed and cleaned. There are 3 big plates: One under the engine (has a mesh on the front), one under the oil pan/transmission and another under the fuel tank. An application of rust converter followed by POR15 or bedliner should take care of it. I will also shoot rust proofing spray inside the frame rails and any cavities.
But then, I found some mud and gravel stuck under the protective covers on the KDSS accumulator. I removed the covers to see reveal a horror story underneath! It looks like mud got stuck there and caused galvanic corrosion between the accumulator body (Aluminum) and surrounding steel. The accumulator is hardly recognizable with all that rust around it. I chipped as much as possible and will spray it with some rust inhibitor to stop further rusting.
I believe the truck may have been stuck in mud on this side only since the rest of it is clear and doesn't have any encased mud anywhere else. I'm probably lucky in this regard otherwise I would have been cleaning mud for days..
I thought of sharing the info with you so whoever lives or drives in the salt belt to check these areas for rust and corrosion.
the kdss cover has x2 12mm bolts
KDSS Protective cover KDSS Accumulator (where is it?)
Fuel Tank skid plate
Rust converter applied (before drying)
thanks for sharing this, it prompted me to go check mine!
stubborn bastards
road tar and salt
wire brushed as much i could. if anyone knows what i could use to remove the caked on salt, please help!
bathed it in white lithium.
Last edited by WRD4chano; Dec 10, 2021 at 05:21 PM.
I would recommend a few things here, although it looks like you’ve done a nice job intervening and arresting this corrosion already. 1) avoid bed liner protective coatings. They tend to bubble or blister, trapping fluid and making corrosion worse. 2) Solution of baking soda and water to scrub the aluminum oxidation with a stiff brush until it’s gone. You must get all of the “white powder” oxidation removed or it will simply continue. Once it’s completely clean, prime it with an aerospace chromates primer. 3) Apply a Corrosion Protective Coating (CPC). Fluid film works great inside frame members and body panel drainage holes. CRC marine grade CPC wax film works best on exposed chassis surfaces and electrical connections (in my opinion). It dries much like wax, is only slightly tacky, is long lasting and self healing.
The problem we are starting to see now is that chromated protective coatings on steel and aluminum were phased out/eliminated mid 2000’s in favor of environmentally friendlier finishes. These new finishes simply do not protect anywhere near as well as legacy chromated protective films/finishes.
I do know a little bit about what I’m talking about, as I ran the corrosion prevention program for one of the USAF’s most utilized legacy aircraft. We have the same problem in aerospace on our new aircraft and also repair / refurb finish systems. Air Force is going to a sacrificial magnesium based finish system combined with trivalent chromium treatment for aluminum (which basically doesn’t do much more than help paint to stick better). Increased aircraft wash frequency based on location.
So, what can we do? Wash…wash…wash. Washing your car, both the body, interior, and chassis is the best thing you can do to prevent corrosion. You cannot stop it. It is a pervasive menace. You can only slow it down by cleaning, treating, and repairing when you find it, much as this gentleman has done. On my GX, every time I change the oil I am armed with a wire brush and can of rust oleum rust converter, hitting everything I can see. I also purchased a rolling undercarriage pressure washer attachment for home washing and an unlimited membership to my local car wash where they have a great under carriage blaster.
Rust horrors!!
). To make things easier, I picked up the
and
off Amazon. In addition, I let the 1 gallon sit in the sun (ambient temp was about 75 degrees that day) for a few hours which aided in making it more liquid like and therefore easier to spray/manage. It still took me about 8 hours on a Saturday to complete the project since I removed the wheels (including the spare), skid plates and covered the brakes/rotors before spraying. I did it all in my garage but in all honestly not sure I'll do it again under those conditions since crawling around on a concrete floor isn't exactly my idea of fun at my age. I'm convinced a lift is needed since you can stand, have better sight lines and better angles which would certainly have sped things up. Overall, I'm happy with the results and hope it provides at least a couple years of protection since I don't plan on repeating it every year. On a side note, a lot complain about the smell but initially it didn't seem that bad after opening the can and taking a big whiff. However, I fully understand after spraying/smelling it for 1/2 a day. 
