![]() 04/12/2019 at 18:40 • Filed to: None | ![]() | ![]() |
Two Questions:
1. Any experience with this?
2. How much likelihood that the rim might structurally fail?
A fellow teacher bought a set of 17-inch TRD rims for his 2016 Tacoma and one of them developed a leak caused by porosity in the rim. I’d never actually heard* of that, but it was my first guess and I was correct. He is working with TRD to see if he can get Toyota to replace the rim for him.
Thoughts?
Thanks.
![]() 04/12/2019 at 18:53 |
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0 posts about rim porosity on TW, and those guys post about everything..
https://www.tacomaworld.com/search/8138667/?q=porosity&t=post&o=date&c[node]=15
Are these Repos
? Is the dealership replacing them?
![]() 04/12/2019 at 18:55 |
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This is really not my area at all, but I told my friend that folks here would know stuff. He didn’t get them new on his Taco, but bought them afterward. I believe...
![]() 04/12/2019 at 18:58 |
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If a rim was porous, it would have leaked right away. Unless they somehow got something like lye on the rim and it ate the aluminum.
Most likely he curbed the ever loving shit out of the rim and cracked it near the bead.
![]() 04/12/2019 at 19:03 |
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One, porosity defects MUST be covered under warranty of merchantability . No exceptions - that’s UCC (Uniform Commercial Code.) Porosity may also be a safety defect; out of spec porosity in critical areas may result in further fracturing of the rim. Note that standard warranty limitations do still apply, so if the claim was made within standard warranty period, Toyota doesn’t have a leg to stand on. A wheel sold by the manufacturer is expected to be safe for purpose and hold air, and meets neither. If it fails the dunk tank, Toyota owes them a new wheel (if it’s within the warranty period. Yes our laws are a total joke in that regard. )
This does not mean it is porosity. I’ve heard that excuse more times than I can count. Porosity failures absent visible or detectable cracks or other immediately provable tests are vanishingly rare . In fact, GM (whose flaky chrome rims were notorious for porosity failures) has an entire procedure for confirming pororisity failures which amounts to “inflate from 33PSI to 40PSI, throw in dunk tank.” They also have a repair procedure. (Don’t repair non-GM wheels without explicit manufacturer specifications and guidance. GM knew exactly what the tolerances were and had very strict limits on how much could be done .) More often than not, shops will bullshit about porosity when in fact it’s bad mounting or bad tires.
Nobody other than the foundry that actually cast the wheels can tell you what the risk is - porosity is calculated using metallurgy, casting method, cooling rate, the form, and a lot of other proprietary data. The form also dictates the acceptable level of porosity since a certain amount of porosity may be expected. Plus the finishing on the wheel provides a further air barrier. Which is why true ‘porosity’ leaks are
uncommon on most modern wheels.
![]() 04/12/2019 at 19:06 |
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Well, this guy is
super
-fastidious about his truck and if he had done, I think he’d have mentioned it in our conversation.
![]() 04/12/2019 at 19:07 |
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The pathway through the material, i.e. the defects or crack initiation sights, are very small. Also, porosity is more common than leaking porosity - it just goes undetected. The risk of sudden, catastrophic failure is quite low for slow leaking porosity. If any failure at all occurs, it will be a crack, which will leak much faster, obviously.
Alllllll of that said, it certainly increases the risk by some amount, statistically speaking. They should be replaced, the leak is dangerous in itself.
![]() 04/12/2019 at 19:08 |
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I would think fix a flat stop leak would be perfect for such a problem...
Here’s some other ideas https://www.jalopyjournal.com/forum/threads/aluminum-wheel-leak.325458/
![]() 04/12/2019 at 19:10 |
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I believe a tire shop patched the inside of the rim with a rubber tire patch. My friend is going to give them the wheel and they’re going to send it off to TRD or Toyota, or whatever. There is a mark on the surface of the rim about the size of a finger nail as Alex described it to me.
My brother’s -- Ttyymmnn -- Honda Odyssey developed an engine oil lead from a porosity issue with the block which, I understand, happened from time to time with that particular engine. This is what caused me to immediately ask about porosity. I told him I thought that if indeed he had a porosity issue, that it would be a fluke.
![]() 04/12/2019 at 19:13 |
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Thanks. They’re taking the other car tonight on their trip until he can get the rim replaced.
![]() 04/12/2019 at 19:13 |
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Tire shop stuck a rubber tire patch on the rim at the point of the leak.
![]() 04/12/2019 at 19:18 |
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Works for me. Aluminum can be porous. Not a big deal unless it looks like this....
![]() 04/12/2019 at 19:18 |
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In order for porosity to be bad enough to affect it structurally, it’d have to be really bad, and definitely noticeable
. Cracks are not porosity, and would increase the risk of failure.
![]() 04/12/2019 at 19:20 |
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No, nothing like that.
![]() 04/12/2019 at 19:21 |
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Would be my thinking. I don’t think he has an imminent structural failure, but If it were my rim, I’d be wanting Toyota to replace if if I hadn’t curbed it.
![]() 04/12/2019 at 19:23 |
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And right there, that’s an automatic fail, and the absolutely incorrect way to do the job regardless of the wheel. There is a very, very specific procedure because of the acids and outgassing involved. If there’s an actual mark on the rim that’s visible, then it’s not porosity - it’s cracked. Porosity fails dunk test but not visual test. Toyota might also reject for improper repair / abuse if there’s an actual published guide for repair.
Engine porosity issues are more common in older tooling and cast iron blocks simply because of the nature of the beast. I don’t pretend to understand all the details, because I don’t, but they’re “just something you live with.” (Though I’ve been told that it also has a lot to do with maintenance of the tooling or lack thereof, LOOKING AT YOU HONDA. And Chrysler.) Wheels on the other hand, are usually gravity cast alloys or forged, so supposedly there should be less porosity risk.
Actually understanding the causes of porosity though? Fuck, that is miles beyond what metallurgy I do have, which ain’t fuckin’ much. Mohs, RoHS, machinability, thermal expansion , weldability, and compatibility is all I got there.
Oh. Right. And RootWyrm’s SGBH scale. (Suitability for Grevious Bodily Harm.) Stainless steel stock is about a 7.5/10.
![]() 04/12/2019 at 20:01 |
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I had 2 mountain bike rims explode to this. good times.
![]() 04/12/2019 at 20:37 |
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Yeah, porosity
definitely would be a manufacturing defect. I’d assume there should be some kind of warranty with them.
![]() 04/12/2019 at 21:18 |
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I never heard of it till Urambo did his JRITS post
I don’t know if it would fail, but I would bet it would be more likely to fail before a proper rim. There is an airpocket weakening the spoke.
![]() 04/12/2019 at 23:29 |
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If you’re going to offr oad the hell out of it get steelies, like Cragar’s or something. Otherwise I’ve never really heard of too many people cracking their rims unless REALLY aired down.
![]() 04/13/2019 at 01:09 |
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Yeah, though off-roading isn't my hobby area, I did tell him I thought steel rims made sense. But he does a lot of highway and he doesn't crawl over rocks or anything, just does a lot of exploring.
![]() 04/13/2019 at 09:01 |
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He's going to replace the rim one way or the other. It's usually interesting to get Oppo's take because there's lots of highly varies interest and experience.
![]() 04/13/2019 at 09:03 |
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And an extremely rare defect at that.
![]() 04/13/2019 at 09:04 |
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Ew.