Realistic impact of rust on longevity (1 Viewer)

[RockDriver]

I've been looking at some 120s on the market. Rust is obviously a number one problem in my region, but I see lots of owners just not giving a ѕhit about that. So I was wondering realistically just how long can a 120 last in such a scenario? Have any of you seen or heard of severe cases when the frame was catastrophically compromised by rust? What is the actual lifespan of say a 20 year old 120 with significant rust? 5 more years? More? Less?

There's a minority of owners who seem to do the rust proofing, but even that seems to be controversial from what I've discovered so far. So what's the healthy level of paranoia when it comes to rust?

 

[Sixto Lezcano]

Rust never sleeps. If you don’t treat it your frame will crumble. Especially right front passenger side under the AC drain. There are lots of pictures of rusty frames here if you search. My experience is that our GX’s are particularly prone to rust. I’ve got an old BMW and an old Land Rover and they are both in far better condition and much easier to work on.

I recently had my gx frame repaired and then coated in por15. It was not cheap, and I understand it wasn’t a permanent fix, but it will buy me a few more years. My entire rear crossmember was gone and if I hadn’t gotten it fixed I wouldn’t have felt safe driving it.

 

[rommelrommel]

If there is visible heavy rust it's likely the frame has very little strength left somewhere, so who knows how long you might get.

And yes, lots of people have posted their trucks over the years or ones they went to look at that had either catastrophically failed or were right on the verge.

 

[RockDriver]

Rust never sleeps. If you don’t treat it your frame will crumble. Especially right front passenger side under the AC drain. There are lots of pictures of rusty frames here if you search. My experience is that our GX’s are particularly prone to rust. I’ve got an old BMW and an old Land Rover and they are both in far better condition and much easier to work on.

I recently had my gx frame repaired and then coated in por15. It was not cheap, and I understand it wasn’t a permanent fix, but it will buy me a few more years. My entire rear crossmember was gone and if I hadn’t gotten it fixed I wouldn’t have felt safe driving it.

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That's interesting. I have a lot of questions. Did the body have to be lifted from the frame for this procedure? Was the rear segment manufactured or cut out from a donor? How much did all that cost? Did you do any rust proofing afterwards?

 

[Sixto Lezcano]

That's interesting. I have a lot of questions. Did the body have to be lifted from the frame for this procedure? Was the rear segment manufactured or cut out from a donor? How much did all that cost? Did you do any rust proofing afterwards?

The body did not have to be lifted from frame, but they did drop the gas tank. The rear crossmember you see in the picture is a part from Lexus, it was about $650 I believe. The frame is now coated with por15, I will try and take a few pictures today but it’s definitely a lot better than it was. It cost around $3000. I have quite a bit into the gx and, aside from rust, it is a great ride. So for me, a few grand to keep it going was worth it.

In hindsight I would have bought a southern, rust free gx and gotten it undercoated, but I bought this years ago before I knew much about them, I just liked the way the gx looked at the time! Overall it’s been a worthwhile and enjoyable experience despite my many mistakes.

 

[Rednexus]

The frame steel in these rigs is only 1/8" thick. The factory coating on the frame kind of sucks, and they will often start rusting at the welds first, and then progress after that. Junk can also get trapped inside the frame and rot it from the inside out. I would pass on any rig that has more than surface rust, and give the rig a full inspection inside the frame with a camera. As mentioned above, the AC dripline can make rust worse on the passenger side frame rail. I relocated mine so it drips under the frame and straight on the ground. It'd a shame that Toyota never bothered fixing that in 20+ years on multiple rigs, considering it cost me all of $10 or so to relocate it.

Mine was not too bad, but covered in surface rust. I undercoated it with Woolwax (outside) and Fluid Flim (inside) in 2021 and re-applied earlier this year. It stopped rust progression. But, I have a climate in between the terrible North and sun-baked south. Living further north than I do would probably require annual applications.

 

[zzyzx85]

even though i'm in SoCal and I'm pretty sure my GX's frame is rust free, i'm still tempted to buy a few cans of Fluid Film to spray inside of the frame. good idea? I've already moved the AC drain to exit below the frame.

 

[rommelrommel]

even though i'm in SoCal and I'm pretty sure my GX's frame is rust free, i'm still tempted to buy a few cans of Fluid Film to spray inside of the frame. good idea? I've already moved the AC drain to exit below the frame.

Doesn't hurt. Places that do it have all the little nozzles to get in the various frame holes but I could see it helping.

 

[jlieu]

Some are already in a bad state depending where you live. Here in the North, I've seen some priced quite low (sub 5K or less) and it looked like the fuel line and other parts were a bump away from snapping.

However, I will say despite being 15+ years old; I've seen some rusty ones here that were not that bad (for a northern vehicle). The biggest areas most notorious for rust that I've seen is passenger front frame (under AC drain) and the rear crossmember (fortunately this can be cut off and available by Lexus/Toyota to be welded on).

I grew up in the South, but spent the last decade or so in the North; so learned a lot about undercoatings since then. I've asked my wife who is a polymer scientist/chemist a ton about the common products (POR-15, Fluid Film, Woolwax, Cosmoline, etc.). While she agreed that POR-15 and Cosmoline can be effective, she said it tend to be best with newer metal with minimal rust OR a wide open area that can be prepped properly with high success (such as a truck bed). For these particular products, prep work is of the utmost importance otherwise it can have the 'rust from the inside out' dilemma. Because of that, she recommended Wool Wax/Fluid Film and other similar lanolin products for older/rusty metals. It won't convert the rust, but you also don't need to prep it nearly as much and it will essentially 'stop the rust' as long as the coating is maintained.

Going back to your original question...with significant rust, maybe 5 years if you don't do anything to it? If you apply some undercoating, should last much longer assuming the frame is still solid for the most part. If it's moderate rust, it can easily go another 10+ years with some lanolin treatment from my understanding.

 

[CarGuyCarl]

I first noticed the relatively horrifying looking rust on our 2006 in 2020. I have since wire brushed it, rust reformered it, and probably put 4-5 cans of fluid film through it yearly.

The rust in places still looks awful. I haven't removed the rear bumper, but I'm sure that's rough. The AC drain now has an extender kit, but the damage has been done. There is lots of rust there and the weld between the two sections of frame has disintegrated there.

There are lots of crispy spots on my truck, it's been in Chicago since new and didn't get lots of care until 4 years ago. I will say fluid film has made an obvious impact to the progression of rust.

Rust can be hard to gauge but especially if you're in a rush. Get under there and poke at it with a screw driver.

 

[Hardazclay]

Are there kits to extend the AC drain that anyone would recommend?

 

[Sixto Lezcano]

100-Series / LX470 / GX470 AC Drain Extension Kit — CRUISER GARAGE

AC drain line extension kits that fit all 1998-2007 100-Series Land Cruisers / LX470's and 2003-2009 120-Series / GX470’s. The factory AC drip line is situated perfectly above the vehicles frame and passenger side sway bar bracket. A common issue with Land Cruiser 100’s and 120’s is rust in this loc

cruisergarage.com

Or just make your own, I used this plus a zip tie and some 3/8 tubing I had in the garage:

https://www.amazon.com/dp/B0D6WDXM8F?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

 

[zzyzx85]

Are there kits to extend the AC drain that anyone would recommend?

there are but I just pieced together a "kit" from Lowe's. The clear vinyl tubing might not be ideal but it's working just fine.

 

[JAGI410]

If you look at some of the 4Runner rust stories, some of those folks are still driving cross country on Swiss cheese style frames. I have yet to see a catastrophic failure of a frame due strictly to rust (if you have one to share, please do!). The GX Community seems to panic at the first orange spot and deem these things totaled.

Mine has rust, and I bought it knowing that it did. Safe-t-caps are cheap, and until I'm ready for that step, Fluid Film is even cheaper. But you know what's free? Not looking underneath!