Undercarriage Rust on T4R

[jeskandarian]

Would you purchase with this much rust? Sorry can't start a thread

Just had my daughter's fully built Wrangler TJ stolen so I'm looking at a 4th gen 4R (4WD) as our next project. I live in Southern CA. I've looked at a couple that have had rust thru on the frame rails. Our budget is around $17k.

I would have to fly to NM to purchase this one and I had the sales guy take photos underneath. I'm sort of horrified by the rust but it seems most 4WDs came from the East coast and this just may be typical. Any input is appreciated.

 

[t4r-4-mtb]

Just had my daughter's fully built Wrangler TJ stolen so I'm looking at a 4th gen 4R (4WD) as our next project. I live in Southern CA. I've looked at a couple that have had rust thru on the frame rails. Our budget is around $17k.

I would have to fly to NM to purchase this one and I had the sales guy take photos underneath. I'm sort of horrified by the rust but it seems most 4WDs came from the East coast and this just may be typical. Any input is appreciated.

I've spent the last few months looking at, and attempting to buy, a 3rd Gen 4Runner. Those which were clean and rust free tend to sell immediately and I seemed to respond 10 min too late. I even committed to fly to Irvine from SJ to buy a fantastically clean one but was told that he had "just told another guy 5 min ago" that he could buy it. Interesting, because I had told him I was serious and he spent 4 days sending me various photographs to confirm condition and upgrades.

I did end up finally buying one that had spent time in Colorado and other snowy states. It has some light to moderate frame rust which I will clean up over time. For me, the photos you posted have too much rust, unless you are getting a killer deal on the truck. There are always going to be trade-offs, especially with older vehicles like these. But, with the amount of rust on the photos you posted --> 1. there are much cleaner vehicles out there but it may take a few days/weeks/months for them to pop up for sale 2. if you buy that vehicle, you may want to take it to a restoration specialist to have it cleaned up. Some of it is just surface rust but there's likely some that will require parts replacement. Given that your daughter's Jeep was fully built, this is likely not an issue for you as I would imagine you will be building the 4Runner as well, right?

Good luck with it all!!!

 

[jeskandarian]

Building a vehicle is one thing but to me fixing rust damage is not something I want to take on.

This one might be beyond the point where stopping the rust is good enough. I don't know enough about these to know if what I'm looking are attempts at repairs or if it's just surface rust on the original frame.

I've spent the last few months looking at, and attempting to buy, a 3rd Gen 4Runner. Those which were clean and rust free tend to sell immediately and I seemed to respond 10 min too late. I even committed to fly to Irvine from SJ to buy a fantastically clean one but was told that he had "just told another guy 5 min ago" that he could buy it. Interesting, because I had told him I was serious and he spent 4 days sending me various photographs to confirm condition and upgrades.

I did end up finally buying one that had spent time in Colorado and other snowy states. It has some light to moderate frame rust which I will clean up over time. For me, the photos you posted have too much rust, unless you are getting a killer deal on the truck. There are always going to be trade-offs, especially with older vehicles like these. But, with the amount of rust on the photos you posted --> 1. there are much cleaner vehicles out there but it may take a few days/weeks/months for them to pop up for sale 2. if you buy that vehicle, you may want to take it to a restoration specialist to have it cleaned up. Some of it is just surface rust but there's likely some that will require parts replacement. Given that your daughter's Jeep was fully built, this is likely not an issue for you as I would imagine you will be building the 4Runner as well, right?

Good luck with it all!!!

 

[Monty87ls]

​

The welder I had fix the rad support on mine said use transmission fluid. Clean it maybe treat with something then spray some transmission fluid in the frame and outside. He has 3 tacomas ranging from 1992 to 2009I think it was. The frames looked perfect on all 3 with a nice heavy coat of fluid on them. Dirty yes but no rust! and we live in NY!

 

[rdruss]

jeskandarian, that one looks pretty good to me. you will be spending some time sanding and painting and probably cutting the alignment hardware off the LCAs and replacing with new/greased ones, I Have an '03 I bought used and live in northern Illinois so am constantly battling rust and it is a PIA.
Check under the passenger side front door/bottom of frame rail, that's where the AC condensate accumulates and rusts the frame pretty bad. You will want to re-route that AC line to the wheel well.

 

[Syr4RinNC]

Building a vehicle is one thing but to me fixing rust damage is not something I want to take on.

This one might be beyond the point where stopping the rust is good enough. I don't know enough about these to know if what I'm looking are attempts at repairs or if it's just surface rust on the original frame.

There really shouldn’t be any issue with that - from what I see it’s all cosmetic and none of that should cause any long term problems particular if it’ll live in CA. You can again sand it and apply a rust converter and repaint if it bothers you but I think it’s extremely unlikely to be a problem for the next 15 years or so.

The biggest issue you may have is that some of those bolts may be seized and difficult to get off

For someone from the rust belt I wouldn’t think twice about that

 

[j4run]

Just had my daughter's fully built Wrangler TJ stolen so I'm looking at a 4th gen 4R (4WD) as our next project. I live in Southern CA. I've looked at a couple that have had rust thru on the frame rails. Our budget is around $17k.

I would have to fly to NM to purchase this one and I had the sales guy take photos underneath. I'm sort of horrified by the rust but it seems most 4WDs came from the East coast and this just may be typical. Any input is appreciated.

I purchased a 4Runner with rust very similar to what's in your pictures. That rust does not look like a structural issue, as is. If the rest of the car and the price are good, then your task is to find someone that will apply an effective rust inhibitor. I purchased (and apply) Fluid Film. This stuff works great at stopping further rust, but it needs to be reapplied (to exterior surfaces, inside the frame, above the spare tire, etc.) every 2-3 years to keep the rust as-is. This isn't a huge deal, but my impression is that most daughters are unlikely to do this. There are other similar products (I like the lanolin ones best ...). If the car is going to a "low rust" climate, you'll be fine for a long time if you inhibit further rust and retreat it occasionally.

It's a huge effort to remove the rust (.. ask me how I know ...) and I couldn't imagine paying someone to do this. It would be less expensive and a lot less trouble to buy a newer model. So the value option it to stop the rust now, before it's an issue, and keep it that way.

 

[Syr4RinNC]

I did my 4runner best I could a few weeks ago - wire wheel, rust oleum rust converter then fluid film

Was applying fluid film to our other vehicles - Highlander and ram 1500 and the ram has a lot more rust than I expected. Should have definitely hit that with rust converter first. Next summer I’ll have to try to clean it off those areas to treat better

 

[Ujanti]

From lots of research on these forums, a rusty frame is the single largest weak spot on these trucks. I would strongly suggest doing all you can to find a unit that has little to no rust. Being from Wisconsin, this is a large concern for me as well. I went out of my way to get one that fit this criteria and even then I will be fluid filming the frame inside and out to prevent the rust from forming the best I can.

Here are a few pics of mine to show what I thought was acceptable:

 

[Mindyboy]

2004 4th gen rust

Hi All,

I have just purchased a used 2004 4th gen 4runner and it was quickly and I feel costly decesion due to frame rust and need advice what i need to do resolve the issue.

 

[Mindyboy]

more photos

 

[Syr4RinNC]

more photos

So, it depends.

Are you hoping to use this forever/ indefinitely or for a few years?

Where do you live and is there ongoing exposure to salt?

How much time/ budget do you have

Do you care how it looks, or just want to make sure it doesnt rust through and become unsafe to drive?

The other areas I would check are the radiator support under the front of the vehicle. The frame near the passenger front wheel well/ door - The AC drain is here right on to the frame for some reason and can be a cause of rust. and the rear cross member under the bumper cover. Those will be the most likely spots to rust significantly

You could do nothing and just watch it regularly. If your state has state inspections, someone will have to get under once a year. Otherwise, anytime you have to bring it in, theyll generally do a quick safety check before putting it on a lift

You could try to remove all the flaking/ rusting metal you can. Scrape it, needle it, sand blast it and then use a rust converter and paint it

You could look into professional shops for rust mitigation/ repair

 

[mssVT98]

Hi all,

Sorry to resurrect an old thread but this seemed like as good a place as any rather than waiting to start a new one.

New member here, I have an 06 4R Sport V6 that's coming up on 180k miles. I've only recently started doing more of my own maintenance on it, and as such am getting under it for a good look for the first time. My concern, probably unsurprisingly, is rust. I've only done a surface-level look so far, and plan on getting under it again this weekend to look more closely. There's definitely a good bit of surface rust, but also a couple of areas that are more concerning to me. Forgive me for any incorrect terminology wrt the 4R and its components, but this is where the front suspension connects to the subframe (pics attached).

I'm interested in feedback on how bad this is and what remediation makes sense. I'm at a point where I need to make a decision on how to move forward given the mileage and other work I know the truck needs in the not-too-distant future (strut replacement being the primary one). I've seen other posts and videos about wire brushing/treating everything under there, but if this is going to require more extensive work, or it's not worth it at all, I'd rather figure it out before getting started on all that. I'm happy to take more pics this weekend but at least wanted to get some initial thoughts.

Thanks!

 

[Syr4RinNC]

That rust is pretty mild. I dont think your frame is gonna rust out anytime soon. You can certainly go ahead and wire wheel, rust convert, but may be a tough area to get it all

good luck

 

[MikeinNH67]

That doesn't look bad, just the coating Toyota applied chipping off. Scrape it off and see how it looks after that. The areas you need to watch are the bottom flat areas of the frame near the bottom of the axle arches, the front tow point areas and the frame behind the bumper cover.

 

[mssVT98]

Thanks to both of you, appreciate the clarity there. I hadn't thought about the coating flaking off, but yeah, that does seem likely. I'll get a better idea this weekend of what the trouble areas look like and plan from there. I don't know that we're looking to keep this thing through 300k or anything but I definitely want to head off potential showstoppers before they get to that point.

 

[andynj]

+1 to wire wheeling and poking with a screwdriver to see how deep it goes. From pics it looks like just surface rust and can easily cleaned up. I used the Eastwood rust converter and chassis paint on mine and it worked great and is holding up fine in NYC after 5 years although I also woolwax every other year.

One tip is also to drop the skid pans in the front, I just did a CV job and found some rust starting there on the arms next to the diff that needed wire wheeling and paint as it gets blasted by water and salt.

Its not a super fun job but highly satisfying and worth taking time over as a good job will last years. I did my whole underbody in 1 weekend when I got the car 5 years ago including the inside of the frame rails with Eastwood internal frame paint and its still looks perfect with some minor touch ups in the spring.

 

[mssVT98]

Ok so I did a little further looking this morning, and there were two areas that look like actual concerns. First, as mentioned, was behind the rear bumper. The are two holes on the driver's side corner, and the passenger corner looks a little rough too. There is a good amount of surface rust at least running the length of that section.

Second is right next to the cats. This looks like it's getting a little deep as well.

Thoughts?

 

[Buckaroo]

Yes, I think heat from the exhaust system can contribute to frame rust so locations next to CAT & muffler are susceptible. Common problem with 3rd & 4th gen T4R's in the snowbelt. Looks like you have frame rail perforations that should be addressed but not necessarily the end of the world. Plate can be welded in at that point to strengthen the rail and, depending on location, there are ready made fabricated patches like this....
All SafeTCap(R) Frame Repair Kits for 03-09 4-Runner - autorust.com
Need to find a competent welder and may want to start with someone who does frame restoration. After fixing that, I would apply a product like Woolwax over the entire frame to slow down future corrosion.

 

[MikeinNH67]

Ouch, yeah those are the areas that are at issue. Salty sand seems to sit in some areas so they rust from the inside out. Sadly, once all the rust is removed those holes will be huge. You're going to have to decide what you are willing to put into it for repairs, if that's even possible at this point and know that it may only be good for a few years at best. The Safe-t-caps mentioned are a good repair but you will end up with more holes elsewhere at some point.

BTW, having someone repair that will cost into the thousands, that's assuming you'll find someone to take it on. Sorry to say, but those pictures put that 4runner into the parts car range for most people.