Rusty Frame Questions (Gen 2 Tacoma)

Hello Everyone!

I was under my truck last week undercoating the frame with woolwax and noticed rust forming on the boxed section of the frame, on the passenger side of the truck. It was treated with CRC, by Toyota, before I owned the vehicle. I took off the cap that blocks off the boxed section of the frame and started digging around... I ended up pulling out a few chunks of rust from under the CRC coating that opened up a few holes in the frame. I have looked over the rest of the truck and no other sections besides this seem to have much rust. However, the bottom 1/2 of the frame where the rust holes are, is very thin.

My two questions are...

1. Is there an effective/easy way to remove the coating Toyota applied to these frames? It seems like, in this instance, they ended up trapping salt and moisture in the frame which rusted it out. I noticed they plugged two of the drain holes with the CRC crap near where the frame rusted, which could not have helped.

2. How would you address this issue? Take it to a fab shop? My wife frequently drives this vehicle and the rust will, obviously, only get worse... I do not want her driving something that may not be/will not be structurally sound.

Thanks for any input!
-Cal

 

The black Noxudol that was applied during the earlier periods of the TSB is best removed with a scrub brush and mineral spirits. It is a nasty job. The white stuff on the inside comes out the same way and is even more of a pain in the ass because it is inside the box sections and hard to get really clean.

Having dealt with this issue myself, I will give you a little bit of advice:

1) It's going to be worse inside the frame than what you see on the outside. The areas near the cats and muffler, inboard/under the truck, should be checked very carefully and tested with a hammer and maybe even a punch. Pay attention to the cab mount knuckles while you are under there and have them plated if necessary.

2) Thoroughly remove all coatings and residues from the areas where you can see obvious perforations and heavy rust, and then go so far as to use a wire wheel, rotary burr/dremel, files, whatever is necessary to open the rust holes up to good metal sufficiently thick to weld (i.e. chop out as much of the cancer as you possibly can). The box sections can be laboriously cleaned out with a large chimney brush and mineral spirits, then pressure washed out with an added detergent (Dawn dish soap works pretty good to grab loose/thin oils, greases, and waxes). Doing this cleaning yourself will both reduce the labor hours you pay the installer/fabricator, as well as ensure a good fit and a clean weld. You might also use a chain flail to remove any loose rust inside the frame (here's a YouTube link to a homemade chain flail - I did something very similar with my truck https://www.youtube.com/watch?v=_UkIrgl6ha8 )

3) Determine which Saf-T-Caps (autorust.com) will cover the damaged sections of the frame - these are extremely high quality products and the cost of buying and welding on the entire sections is not much more than having a fabricator source and cut smaller plates that only cover the holes, and will give you a much much better long term solution. The installer instructions state to remove the bottom 1/4" of the frame, but if your bottom sections (like mine) are still sound, I found the Saf-T-Caps to be a perfect fit without this step. After installing the Saf-T-Caps, use the breakaway pieces of the Saf-T-Cap to patch the holes from the inside as well, when possible, again to prevent moisture intrusion through the hole.

4) Before having the Saf-T-Caps welded on, apply a quality cavity wax (such as SEM cavity wax) to the frame and the inside face of the Saf-T-Cap, to prevent trapped moisture in the future. After having them applied, use FluidFilm, Woolwax, or similar on the entire frame. I also had my guy weld up the edges of the various frame holes where they met the matching holes in the Saf-T-Caps to avoid moisture intrusion there.

I paid a very good shop less than 500 dollars to install front sections. I will note that it saved him quite a lot of time overall to lift the cab slightly off the frame (remove body bushings) to get clearance for the weld. This would also be a good time to replace the body bushings, since you are already paying for the labor and the parts (from e.g. Energy Suspension) are cheap, and body bushings are one of those things that you often don't realize are quite so bad until you have them replaced. Spring for new hardware if you go this route, the ten or fifteen dollars will save more than that in labor, since your installer will be able to skip straight to cutting off the old and have clean hardware to install the new, rather than dicking around with rusted existing stuff.

Here's a link to the thread about my frame - https://www.tacomaworld.com/threads/frame-rust-dealership-shenans-and-saf-t-cap-install.663600/

And here's the specific post about the POR-15 application - https://www.tacomaworld.com/threads...saf-t-cap-install.663600/page-3#post-26657124

I DO NOT recommend POR-15 unless you really, really get the frame CLEAN and go through the entire ritual (degrease, etch, etc). If you are less than meticulous, you are better off with a decent rattlecan, as less than meticulous POR-15 will peel, flake, and delaminate, trapping moisture the same way a rubberized undercoating does.

 

Thank you for the information! I already went through with a hammer and checked the frame, the only spot that seems to have an issue is the one in the photo. Thankfully I caught it before it got too bad... I was reading on another forum that the area next to the cats is a problem and thought I might as well check while undercoating the truck. There were no visible perforations before I started pulling rust out of the boxed portion. Kinda disappointing, especially since the Toyota dealership plugged all of the drain holes where the frame rusted with the white crap. I will follow your instructions! Thanks again!

 

Best of luck, please check back in with your solution when you get there.