Originally Posted by Bluesky 07

I'll start by saying I'm blessed - my 2007 Sport was virtually rust-free when I bought it in 2014, with only a few mild spots of surface rust. Since you're asking about protection, not repair, I'll assume yours is reasonably clean.

I work on my own truck so my strategy is to look for rust every time I'm close to anything that can corrode - frame, etc.

If there's rust, wire brush it and paint the area with Rust Reformer. In fact, I just wire-brushed and painted my skids the other day. (Splotches are from a defective nozzle; left it that way since nobody sees it anyway.)



If there's no rust, add or restore protection wherever possible. For example, people often have rusted bolts. I spray Fluid Film on the threads before replacing any bolts I remove then add more on and around the head of the bolt once it's back in. Did it when I installed my shocks for instance and when I dropped my skid plates.

Another good example is when you drop the spare to check the air pressure. Spray Fluid Film on a rag and run it up and down the hoist wire, then spray it into and onto every part of the mechanism you can see. Once you get in the habit, it's amazing how much of your vehicle you'll have protected just by taking an extra minute.

This approach, where there's no widespread coverage on large areas of the frame and so on, might not be enough in a northern environment but it's a start and a great way to avoid seized bolts and fasteners.

Originally Posted by rajat

is this rust underneath my 4runner? pic attached.
I'm new to all this. i didn't feel like rust but more of dust with moisture. but I didn't understand why there was a pattern.

Originally Posted by toto

Many of the metal parts on your 4Runner are already protected. That's because it was made in Japan, and they have to do something to protect it from the saltwater in the air on the boat ride across the ocean. If they didn't, the brand new car would look rusty underneath while sitting on the dealer's lot!

Previous Japanese-made cars I've purchased had actual rustproofing materials on them, but my 06 4Runner is the first one I've had where they've instead used either special paint or a clearcoat type of material. But nonetheless, most of the underbody parts are covered, unlike a car made in North America (by any brand, including Toyota) that doesn't have to make the boat trip.

Originally Posted by Moist

Wasn't there a big issue with early 4th gen 4runners with premature rusting? I know my 03 is rusty as all hell, and I live in nebraska.

Originally Posted by 2003V8LTD

I have been able to keep my '03 rust-free even though it lives in MA and has never spent a night in a garage. I used to have a thing for old British sports cars and those things rusted like CRAZY if you didn't take care of them, so I learned a few moves. For my 4Runner I have just used a wire brush and POR-15 sprayed on. Every spring, I just lay out a tarp and put the 4Runner up on jackstands and use a cheapo wand sprayer. Don't be lazy: remove the skid plates and the spare tire!!!

It's not that dirty if you do it every year. You really really need to get any scale -- no matter how tiny -- off before putting on the POR-15.

The mechanicals and electrics of 4Runners are pretty bombproof, and easy enough to fix or have fixed if they need it. But you have to stay ahead of the game with rust and I haven't found anything better than POR-15. It has worked extremely well on the Toyota, despite 2003 apparently being one of the very worst years for frame rust. The car will be 19 years old in a couple of days; I wouldn't be the least bit surprised if I still drive it after 19 more years -- it's basically an anvil!

Originally Posted by 2003V8LTD

I have been able to keep my '03 rust-free even though it lives in MA and has never spent a night in a garage…

…I haven't found anything better than POR-15. It has worked extremely well on the Toyota, despite 2003 apparently being one of the very worst years for frame rust. The car will be 19 years old in a couple of days; I wouldn't be the least bit surprised if I still drive it after 19 more years -- it's basically an anvil!