The rust warranty is on the Lexus website. Key word is "perforation"... surface rust will never be warrantied...
get some por15 on there and then fluid film it regularly, including inside the frame rails... ensure all your skid plate bolts have antiseize on them and also fluid film the heck our of your alignment tabs on the front lower control arms. Good luck. I hate undercarriage corrosion.

 

Should be picking up my 2020 GX luxury within a couple of weeks when registration, etc sorted.
Unfortunately we live in new England in a beach community and it will be garaged in an attached garage during winter. Therefore many good reasons to worry about rust.
Reading through this thread and IH8MUD forum, it seams the top choices for treatment are por-15, fluid film, corrosion x hd, and amsoil MPHD,N along with weekly under carriage washing. sure which direction to go. Fluid film seams the easiest and most straight forward, but I've read it washes off pretty quickly and therefore needs to be reapplied often.

T4FUN, are you still having success with fluid film? How often do you apply and do you keep your car in a semi-heated garage? How often do you wash the undercarriage?

Anyone else having long-term success with one of the other treatments?

 

I use Corrosion X HD on both of my GX here in Minnesota and it's worked extremely well. I usually spray in October and check mid winter and the product is still present in all the high wash areas. I use the Corrosion X sprayer (2.5 gallon) and works amazing.

What I like most about the HD product is the film strength compared to Fluid Film and other products.

 

Looks like a great option. I haven't read any issues with the rear air suspension, so doubt any is these it options would break down the rubber
I looked up the corrosion-x 2.5 gallon sprayer and it's $850 😮

 

@spectrum1c I've been using fluid film for a decade on numerous vehicles and other applications (have turned many people on to it including my brother in law with a wrangler in MD and my BF in san diego living on the ocean with a wrangler)... My brother in law and his friend bought new wranglers last summer and we did an experiment.... we applied FF to my brother in law's rubicon (did nothing to his friend's because he didn't think it would rust after 1 winter)... needless to say his buddies wrangler had substantial frame rust after just 1 winter and my brother's in laws still looks brand new.

For a new vehicle I can't say enough good things about starting to use fluid film from the get go. FF will not reverse rust, it may slow the spread if it already exists (POR-15 if applied properly will stop the spread of existing rust)... it's best used is to prevent rust from forming in the first place. It encapsulates the surfaces with a lanolin based layer...

What I love about FF is it's relatively inexpensive (I bought a gallon, 6 aerosol cans and the internal frame wand 4 years ago for roughly $100 and still have enough left for my application this year.. so that's about $20/year in cost to keep the undercarriage rust free). Time wise it takes me 4 hours to thoroughly coat the entire undercarriage each time I do it. Each application lasts roughly a year based on my experience but doing more often wouldn't hurt... I don't see any value in power washing the undercarriage of a vehicle which FF is used on... if anything you're breaking down the layer at that point creating areas where rust could form.... I would only power wash the undercarriage (or wash it) just prior to reapplying the FF as a prep step....

I've been using it our GX with excellent results (same as previous vehicles). if you have any specific questions regarding DIY FF application feel free to DM me... best of luck and congrats on the new ride!
One application note: before applying I put the airbags on high setting and stick my hand with a rag up there and coat them completely (dryrot can happen on the bags over time here in the arid texas climate with them left on a setting (not exercised regularly) cause the bag is set (and stressed) in one configuration.... )... I raise and lower our GX monthly and keep the bags coated in FF to prevent rubber dry rot, but again this isn't required just me being **** retentive... the bags are a relatively easy swap anyway if they do happen to fail after a decade or so...

 

Thanks for your reply Nuclearn8. Your image says you're from Texas. I thought frame that wasn't an issue in Texas?

Looks like some people have had success with this harbor freight sprayer for spraying frames (at least it's been mentioned in a couple of reviews)
https://www.harborfreight.com/64-oz-...kit-62895.html
I might give it a try.

 

Only been in TX since 2017.... learned the benefits of FF while living in PA rust belt.... and old habits die hard so I keep using FF even though it's really no needed down here in north TX. the aerosol spray attachment on amazon works will to get inside the frame. I hand wipe or brush FF otherwise (feel like I have better control of where it ends up). I only spray the interior of the frame rails....

 

On my 2007 GX470 (recently sold and purchased a 2019 GX460) I used a combination approach for corrosion prevention on the chassis. For exposed surfaces, CRC Marine Corrosion Inhibitor (dries to a soft waxy film) on everything, including wiring, connectors, CV's, springs, frame, links, driveshaft, etc. For internal frame areas, rocker panels, internal door/trunk/hood through drain holes I fogged in fluid film. For hinges and moving parts exposed to the elements I use Corrosion X. They all have their use and serve an individual purpose. In the fall, i pressure wash the entire under side and then spot touch up any rust spots with a wire brush and rustoleum rust converter. top coat that with CRC Marine Corrosion Inhibitor. It's about a full day's work once a year. But, I live in the rust belt and my GX470 had zero rust on it when i sold it. Well worth it. Now, I have to maintain the GX460 in the same manner!

 

The painted steel parts on the underside of the GX WILL rust if you don't take preventative measures.

FF or Corrosion X debate is like oil or ATF choices.....Not going to get into that

Without something else present that will create a barrier on the metal surfaces, it's a 100% guarantee that corrosion will happen very quickly on the GX. Toyota is known for crappy corrosion protection on their vehicles and the above two products will keep your vehicle in excellent shape.

You don't have to be in the rust belt to have corrosion issues.

 

LexusGXFAN,
Trying to get an idea of what I need to get to coat.
How much Corrosion X did you use on initial spraying?
I contacted Corrosion X and the guy there said one can should be enough. I specified midsize SUV body on frame in MN. They do not make the 2.5 gallon sprayer system anymore.

Did you use a lift when spraying?

Thank you.

 

I use the regular Corrosion X (red can or container) for the inside of the frame.

For all other areas, I use Corrosion X HD (green can or container).

For the two GXs that I do, it usually takes about 1/2 gallon of Corrosion X HD (I have the 2.5 gallon spray system), and you're right, doesn't show that available now. Just the smaller sprayer and 5 gallon.

They make the 12 oz aerosol cans of HD and I would order three cans just to be safe. It doesn't take much to cover (the HD version does not creep like the regular version), but you want to have enough product if you're going to go through all the set up, etc to spray. The cans won't spray as fine of a mist of the product, but much cheaper than ordering a spray system.

I use the race ramps that have 14" of height, but any rhino ramps or other ramp will work.

Take your time when spraying, especially the inside of the frame. There are so many access holes that even with an aerosol can, you can get great coverage inside the frame. I also spray some HD inside the higher splash areas of the frame for added protection.

NOTE - Corrosion X has introduced a new product called Corrosion X XD (extended duty) which is a combo between the regular and HD version. I have not sprayed this, but do have the 16 oz trigger bottle to try.

Hope this helps and good luck. Let me know if you have any further questions !

 

thread is still strong and alive.
I used fluid film and applied it same week i drove home gx while still new.
applied it every year for next 3 years.
film is so thick and protective havent had to apply for last several years.
no major rust i see anywhere.

 

No matter what anyone says, these GX's have nearly identical frames to the 4Runners, both rust if you leave them unprotected in states where they salt the roads. i left our 2014 4Runner without any protection since new and this year we had to go in and rust neutralize the whole undercarriage. looks great now but the new GX we just got will be getting fluid film every year, just buy the cans off Amazon and hose down every surface you can touch. should be enough to prevent 99% of the rust that starts. if you find a company that applies it for you they can put it up on a lift and spray into the frame rails, that'll make it even more useful in preventing rust.

Long story short, Toyota frames rust...why... I have no idea.

 

Finished up my annual fluid film undercarriage application this morning.

 

Nice! Looks factory new