Complete Corrosion Protection for my New T4R

I purchased a new 2021 T4R SR5 Premium this past spring. I've lived in the heart of the rust belt (south shore of Lake Ontario) for my entire life, so I know a little bit about corrosion and corrosion protection. I also came out of a 2014 Tacoma TRD Sport, so I know what rusts and what doesn't on similar vehicles. Finally, I used to work at a local Toyota dealership in Service, so I got to see what my friends swore at and what they'd do differently if they were building vehicles.

Seeing that this will probably be one of the last new vehicles I'll ever buy, I want it to last. My son is a former Toyota / Lexus Certified Service Technician, so all maintenance is done by somebody who really knows what he's doing. That left corrosion protection for the upcoming winter as one of the last loose ends I needed to tie up. I thought I'd share what I did and why with my friends here so that maybe some of you can consider the same steps. I'm also wide open to suggestions for further ideas.

The first thing I did was get the insides of my frame coated with the same product that Toyota uses on their latest program to keep Tacoma frames from rotting out from the inside. The coating also comes with a number of plastic plugs to close a number of holes stamped into the frame rails. Don't ask me how I got this done or how much it cost, but trust me, it's worth a bundle.

Second, I got the entire underside of the truck coated with a product called Waxoyl. I've looked at, read about and tried a number of different underbody coatings and I really liked what I saw in this particular product. I also asked them to coat the entire rear axle housing since they are known to rust through over time believe it or not. And yes, the spare tire was out when they did the coating. In case you're wondering, I would absolutely not - under any circumstances - recommend Ziebart undercoating or inner body coatings. The product and the process suck and the "free annual resprays" are just an excuse to get you in the door to twist your arm for additional products and services.

Third, I got all of the inner body areas sprayed with a product called Krown. This is an oil-based product and I really like the fact that it seeps into small areas and seams to protect them. I didn't get it done on the underside because it does tend to wash off and needs to be re-applied at least yearly down there.

Next, I removed the plastic trim above the rocker panels on all four doors. This area - especially on the driver's door - is known to rust out because the underside of the plastic trim piece rubs through the paint right where you can't see it - until it's too late. I cut pieces of Clear Bra with radiused corners and applied them so that they covered an area just slightly greater than the trim piece. This should keep the plastic from cutting through the paint.



Underneath the truck, I applied a liberal coat of Fluid Film to the Transmission Shifter Position Sensor on the passenger side of the transmission case. These are known to corrode and cause hard shifting over time. They can also be a bit of a bear to get off once rusted.

While I had the FF in hand, I applied a liberal amount to the spare tire lift mechanism as well as the top and bottom sides of my steel spare wheel - especially the seam where the center is welded to the rim. Salt and water will sit in this and corrode the wheel - which you won't find out until you drop your spare.

Under the hood on the driver side, I applied a liberal amount of Fluid Film to the Intermediate Steering Shaft. This is the part of the steering shaft with the universal joints and rag joint. For reasons that elude me, Toyota doesn't put any kind of finish at all on the bare metal. When this bad boy starts to corrode and bind up, it will feel like your steering is going loose-tight-loose-tight as you rotate the steering wheel.

Since I was under the front end, I slathered Fluid Film all over the metal power steering lines leading to and from the steering rack. Someday when either the lines or the steering rack need replacement, somebody's going to thank me.

I also coated the entire inside of the Lower Core Support as well as the foam gasket on the front of it that is known to trap both salt and moisture with a decent amount of Marine Fogging Oil. While I was in the area, I also flowed it into the area between the radiator and the core support of the same reason. Marine Fogging Oil is a special oil loaded with corrosion inhibitors for those of you that haven't heard of it.

While I had the Fluid Film in hand, I applied a liberal amount to the front hood latch mechanism as well as the rear hatch latch mechanism. I also laid a nice coat on the striker plate at the base of the rear hatch.

Finally, maybe the most important thing. My son and I removed all four Alignment Cam Bolts from the Lower Control Arms. These are known to trap salt and moisture that allows them to corrode pretty quickly. When that happens, your ability to use them to align your truck goes pretty much out the window. So, we removed them and liberally coated them with Never Seize. As the pictures below show, even though the truck is only 8 months old, they were already starting to corrode. Even though we carefully marked the positions of the cams, the truck goes in for an alignment tomorrow just to make sure.



Did I forget something? Probably, but this is the best corrosion protection program I've ever applied to any of the numerous vehicles I've owned over the years.

The only other thing needed to get the truck ready for snow is slapping on the winter wheels and tires. I scored a nice set of 2019 Tacoma TRD Sport 17" wheels with TPMS sensors on Craigslist and mounted a slightly narrower than stock set of Blizzak DM-V2 Ice and Snow tires on them. My experience has shown that narrower tires are always better on hard packed snow and ice. These will go on in late December.



I hope this rather lengthy post will help some of you that also want to prevent your T4R's from rusting into an early grave.

 

A man after my own heart... I spent the first 24 years of my life in Ithaca, and I know salt and rust! Fortunately now I live in Virginia Beach, but VDOT still throws salt occasionally, so I'm still planning aggressive measures like yours to make my new baby last.

I was going to go with lots and lots of Cavity Wax, and stick the wands into every frame hole I can find... is there a better alternative?

Are you familiar with the products that will develop a "Black Oxide" coating on bare steel? Black Oxide, unlike "Red Oxide" ie rust, is impervious to further corrosion, so its a great way to treat scratches to bare metal.

Also planning to use SL4 Sielectric Silicone Grease to protect the contacts inside of the "Sealed" connectors to things like KDSS Manifold, Diff Lock Actuator and Front Diff Actuator. I've been using it on contacts forever, and its never let me down.

Can't believe those LCA Cam Bolts! Thanks for sharing that... I'll be doing something with those as well... probably when I get the Marlin Crawler gussets and poly bushings installed...

Again, props on the great info and pics!

 

Thanks for posting up your experience! Very detailed and gives me thoughts for the next time I go under to check. I’ve already sprayed the inside and outside of the frame with woolwax and it set up real nice with dirt and dust that stuck to it. I need to concentrate a bit more on the body, insides of doors, and the cam bolts next year. When I put on my lift, I noticed the lower control arms were gritty when swinging free…wonder if that is the cam bolts.

Ive seen pictures of rear hatches rusting along the seams. The inside of the hatch sucks in tons of dust, which would mean the same for the briny mist we experience on wet days in winter. I settled for cleaning out the bottom seam by taking out the handle “cups” and running low pressure water to clean out dist, but I cant do that in winter. Next summer I’ll need to coat it.

I like the idea of using thinner product for door panels for better creep.

 

I did the work in November every year .. change the oil ,,,,grease the drive shafts clean up any rust .. also use high temp paint on the exhaust pipes also ..wire brush the frame welds and use performance paint and also cold galv paint ..rotate tires and inspect all the brake pads and caliper pins.drop the spare tire and wash it and spray silicone on the rubber tires. also silicone spray on the rubber bushings .. 2016 runner looks like new .
today the weather is cold now temps 20-35F ... I put a plastic shield blocking the radiator air flow 80%.. engine runs warming when the cold temps runs better, and the gas MPG increases ..when the cold temps blocking the radiator plastic shield engine runs warmer and the cabin temps are very warm..

 

Wow, excellent job and attention to detail! Seems like you've thought of everything.

This needs to be a sticky!

I've sanded a lot of scale off the underside of mine, and sprayed various oily substances on/in it to limit corrosion, but as mine was 6 years old when I bought it, I'm starting to fear the horse had left the barn long ago.

Removing the plastic trim was a nice touch, I hadn't though of that. I'm afraid to see what mine looks like under there.

 

Im curious to get some details on the radiator blocking that was mentioned. Where specifically and how attached??

 

WHOA! Be careful with that radiator blocking technique. I knew a guy who did that and overheated his car and left him stranded. In winter. He looked like a fool by the side of the road.

 

A working thermostat basically does the same thing as blocking airflow to the radiator. When cold, the radiator is basically completely isolated from the engine until it’s warm enough.

I did the radiator blocking thing for a while on my old honda accord when it was struggling to warm up in the winter. Then I realized it was because the thermostat failed in the open position.

 

I put a plastic piece was about 1/32 inch thick .I put the plastic over the ac condenser covered the ac cond 80%. I took off the plastic top cover and slid in the plastic over the AC cond .then put the top plastic cover back on next to the hood latch I did not increase the temps.. the engine temps rise quicker in the cold weather and the MPG and the ac heater temps rise quicker temp gauge is normal .. I also did this 30 yrs ago on my GM vehicles.
back a long time ago trailer trucks in my area use a cover on the front grill ... then I did it 30 yrs ago and it works very good..

when I remove the plastic cover the air temps rise 50 plus probably in the end of march .............

 

Excellent original write up- very well written and informative! Thank you!

 

Thanks for the rocker panel tip. I have a roll of clear bra on the way.