They're precision manufactured to exactly the wong size.
Acura Crankshaft/Bearing Recall
- Thread starter 86lxjunker
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The main important thing nowadays that can make all the "wrong size" stuff look like baloney. Is machining centers of all sorts can be equipped with inspection probes that check every part, and if it needs more material removed it does the automatic adjustment and recuts it. So that alone makes one wonder what is really going on. I have in the past done macro programming for just that sort of function.
Machining centers are not CMM’s. And machine time is expensive, no manufacturer is going to run a painstakingly long Reneshaw program to “check” each part. You also have to account for tool pressure, and how it will affect your finish as well as your size. Sometimes your 0.005” re-cut ends up being 0.006-0.008 and now you’re completely out of tolerance.
What they’re doing is using tool life predictions on the CNC to automatically compensate for tool wear while performing spot checks with a CMM and/or other specialty checking fixtures on every X part. Tooling going into the machine is first set up on a pre-setter. They have it down to an almost perfect science.
Yeah I guess your behind the times this was 6 years ago. What is more expensive than machine time? A ton of scrapped parts.
I've got many years in all sorts of machinist work experience how much do you have?
Some set ups if you remove the part you can not reinstall it to recut it on the CNC, and then the cost goes up like crazy to manually machine it to fix the issue. Had a part one time that took almost 2 days to reload to cut, a specialized casting, and it was from some other person.
This shows what I am talking about, on machine inspection.
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Yep, Hyundai wanted to give me only a shortblock when my wife's 2013 Elantra galled up the piston skirts and threw aluminum through out the engine. First sign is massive lifter noise and bad performance, as they become starved for oil. The owners should start a Facebook group and obtain a lawyer for a class action for full longblocks.
Been a machinist since I was in high school thanks to School to Work, thankfully my high school is one of the few left with a stellar shop class.
I’ve seen enough CNC’s with enough slop they couldn’t cut a circle within 0.001”, I and any other self respecting machinist would never trust OMM as a final word.
Also CNC/production environments are BORING. Left that world last year.
Bout the same here though I have done some other jobs along the way though. There where no CNC when I started, some tape jobs though with binary lights blinking at you talking tape data .
Yeah been around junk cnc as well. But been around some that have no issues working in the micron range too.
We did ball bar and servo tuning for circular error, and constant probe calibration, like every day some times more.
Watch that stock hangin out the back, I saw a fellow almost have his left arm cut off from that.
No more than 300rpmBout the same here though I have done some other jobs along the way though. There where no CNC when I started, some tape jobs though with binary lights blinking at you talking tape data .
Yeah been around junk cnc as well. But been around some that have no issues working in the micron range too.
We did ball bar and servo tuning for circular error, and constant probe calibration, like every day some times more.
Watch that stock hangin out the back, I saw a fellow almost have his left arm cut off from that.
it’s 304 stainless which I love cutting We have some old G&L horizontal boring mills with tape readers. They’re used solely as manual machines however…. Except the planetary gear sets in them are fried, so those are all gradual works in processes, made gears for one of them a few weeks ago.
At my old job my lathe was the only one without a tool eye for setting tools… it drifted so bad they gave up and removed it entirely. New job is definitely more “doing anything with nothing” unless it comes to manganese steel with a machinability of 0%… that’s a carbide center, you can see how far it got before it exploded into dust! Should make cylinder liners out of this stuff, good lord!
dnewton3
Staff member
It is likely that if your UOA data shows no profound wear metals, you're probably ok. But do realize that UOAs don't see all wear particles; they only see stuff 5um and smaller. So UOAs give a snapshot view of part of the wear, but not all wear. Some portion of using this tool is taking an inference from known good samples (macro data) and then judging your one sample against those.
If you've got a few successive UOAs which indicate no issues, I'd say after 150k miles you're probably OK, and the risk of a dealer tearing into your engine may be greater than the risk of bad journal clearances.
@dnewton3 - Thanks for the info. I also found an article that indicated that Honda only expects 1% of recalled vehicles to have the issue. I have a friend that's a Toyota Master Mechanic that is going to look into the recall for me and give me a recommendation, but at this point my plan is to just roll the dice.
Nobody really knows why these Honda rod bearings were failing. Honda blamed machining problems, but they only fessed up to a small percentage. Lots of folks outside of the chosen VIN’s have had bearing failure. What’s really going on?
I don’t know, but that doesn’t stop me from speculating.
VCM forces the engine to run out of balance.
GDI tends to cause fuel dilution. BTW, all these rod failures are on GDI engines.
10K oil changes + fuel dilution = bearing failure?
My response is to disable VCM, and go to 4K OCI using Valvoline RP. YMMV
I don’t know, but that doesn’t stop me from speculating.
VCM forces the engine to run out of balance.
GDI tends to cause fuel dilution. BTW, all these rod failures are on GDI engines.
10K oil changes + fuel dilution = bearing failure?
My response is to disable VCM, and go to 4K OCI using Valvoline RP. YMMV
VCM has been around forever now on the J35, and in much worse iterations before that caused a multitude of issues, however not bearing failure. The J35 is not a prevalent fuel diluter either, so I doubt those directly contributed to the bearing issue.
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He’s not doubting your speculation. He’s rebutting some of the things you said - and he’s right. The J35 even with DI isn’t a known diluter and previous VCM versions (VCM-1 and VCM-2) were hard on oil, giving varnish and sludge as well as carboned rings but no big history of bearing issues. It’s an issue on the 2018+ vans, which are VCM-3 and DI of course.
So by process of elimination, fuel dilution is basically crossed off. That leaves VCM (which doesn’t have a history of bearing issues on other older engines), crankshaft/bearing issues (Honda manufacturing which they’ve said), and also the OCI you’ve brought up.
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