Tundra engine recall - interesting news

Very good chance it was transmission, it was a while ago and I don't recall the specifics, just that there was some extension with a part of the powertrain. Being the paper hoarder that I am, I'm sure I still have the documentation from that truck. If I dig it up I will be sure to share.

 

I brought up the same point a few months ago. NotRyan rather impolitely informed me that the ladder bearing cap design has been used for decades in various different engine designs without any problems.

That said, I'm used to '70s and '80s iron that used individual bearing caps that were specifically numbered by position on the crank. Those old engines failed in different ways, but main bearing failures were pretty rare.

 

It's also being used by carmakers who aren't having bearing issues as well in a wide variety of engine sizes. If it's a design flaw causing the Toyota engine failures I don't think it's the issue, might be in parallel with another issue or another defect but it's not just the main bearing cap ladder assembly at fault IMHO.

 

The concept may be sound, but the particular application still may not be, due to design and stresses. But who knows.

 

Having 30 years in industrial processes, it is most likely a second or third tier manufacturer problem causing the defect with the main bearings, or even the blocks.
You wouldn't believe what is overlooked on purpose just so a goal of parts per week is obtained.
The work force has suffered for the worst since 2020, most of the old guys retired, and the newer generations just don't have the same work ethic, plus the old guys left so there is no one to train them.
We have Chemical Engineering Co-op students in the bulding, 15 years ago every one of them wanted to know how things worked, have you taken it apart, etc.
Now not a single one of them has this same interest. The US as a production machine is pretty well screwed.

 

It was a valve spring manufacturing defect that affected the new 5.7L Tundras, Lexus LS460s and the Sequoias at the time (2007-08). The valve spring would break and drop the valve into the combustion chamber and there went your engine. Toyota was quick to resolve that problem at the time.

 

That issue persists in later versions of the 5.7. It's one of the more prominent killers of the otherwise reliable as nails engine.

 

Just fyi in case you didn't know, that warranty doesn't cover scheduled maintenance. The ToyotaCare maintenance plan does that and expires after 2 years or 25K unless you got that extended as well.

 

Car Care Nut says the same thing, 19:37 he talks about it...

https://www.youtube.com/watch?v=EyI4ujjxxuk

 

I saw CCNs video awhile ago and that set me at ease on the ladder assy. That just allows them to drop all the caps in at once. After that every cap is bolted individually with 4 bolts. The aluminum ladder has nothing to do with strength at that point. IMO

 

After watching that video again, is there anything that prevents the #1 main bearing from walking out the front?

I'm not sure what "event" took down that engine, but that front main bearing was surely going to soon enough,

 

And as soon as it walks it blocks the oil flow.

 

Some of the failed bearings are shown to have rotated which blocks the oil hole. Is this rotation a cause or result? I was shocked to see the elimination of the location tab on many newer engines. This is only a bad thing if that shell rotated causing the blockage of the oil passage.

 

Exactly! I questioned that as soon as I watched that video. I thought, maybe TCCN removed something from the engine that normally prevents this from happening, but even he seemed perplexed at the design. That did not give me the confidence to pull the trigger on a new Tundra. Surely Toyota engineers did not miss something so critical?

 

That's the billion $ question for Toyota.

 

Couple interesting posts from an engine building site, I guess tabs are no longer really used or required...

Sunday 7th October 2018quotequote all
Just for the sake of conversation and interest:
I've been helping a friend do some some analysis on a certain type of engine, he's basically buying them up cheap, stripping them and inspecting, trying to work out failure modes, how best to rebuild, modify etc. Anyhow, we got one in that was knocking and my diagnosis was lack of oil at sometime. It wasn't permanent, just under load (when you blipped the throttle) and then when you backed off. As expected it got worse as the oil got thinner when hotter so we pulled it and started to strip it.
Don't get too excited, but the two bits I found vaguely interesting were:
1. Up until now every engine (out of only two!) bearing failure was on number two, this one was No.1 and we don't know why.
2. That the bearings (which have no locating tabs and had most of the soft layer missing, but not all) had actually walked sideways in the rod, but not begun to spin. This meant that whilst some 95% of the width had been worn away, there was a higher lip left on the edge where that part of the bearing was hanging into the recessed rolled fillet area. I'm putting this down to some vibration or resonance set up by it being hammered up and down causing it to vibrated sideways.
I did a quick check with the micrometer whilst it was still in the block and the journal is untouched. One thing I did notice was excessive endfloat, but sadly a stuck crank pulley and the need for a beer and curry ended proceedings so we haven't investigated that yet.
Before what I have seen recently I would have written off a crankshaft (or expected a re-grind) when an engine was knocking or bearing material found in the filter, but no longer. It does seem that on some engines if you catch it in time the crank is untouched and all it needs is a new set of bearings fitting.

Sunday 7th October 2018quotequote all
Yes had the same with an engine last year, lack of main bearing clearance (Which was known about on the build, another story) and very high oil temperatures, slight drop in oil pressure, split the filter and FULL of bearing material!
Stripped engine, crank was perfectly reusable, infact, after the extra .001" was ground from it to correct the bearing clearance there were no signs of any damage, even the big ends had not suffered, but were changed, oil pump also fine. Many of the main shells were down to the steel backings. This was with King race bearings. Done a fair few hours and the customer didn't want to stop using it.
Also stripped an MGB race engine last year, one of the intermediate mains that don't feed a rod bering had spun a shell, shell had blanked off the oil hole and survived for god knows how long like it. Again, crank wasn't too bad.

https://www.pistonheads.com/gassing/topic.asp?t=1767450

I found this site by googling overbuilt engines and locating tabs on bearings as I was just curious and here's the AI answer:
Overbuilt engines often do not require locating tabs on main bearings, as modern designs have transitioned to tab-less bearings for efficiency and cost-effectiveness. The primary function of the tabs is to assist in assembly, and many high-performance engines operate effectively without them.

Are these failures just down to something as simple as the bearing clearance? That could explain why some Tundra's are doing fine, they all got "good" bearing clearances, while the ones blowing up didn't. Really hard to believe that we are speculating like this about Toyota's new (7 year old) flagship engine design.

 

The thing that troubles me, is this would be a simple explanation and solution. If that’s what it was, I would have expected Toyota to have found and corrected fairly quickly.

“Design flaw” gets thrown around a good bit, but I never hear what this “design flaw” is. It’s almost like everyone is guessing.

I have no idea either way.

 

Of course we are guessing. We have nothing to go by except for the dribs and drabs that Toyota releases... and what hints our resident insider members here post.

 

The failure modes seem to be fairly consistent, three years in, discounting the alleged "improper cleaning" of the block early on. With 2025 models apparently still exhibiting a main bearing walking out, Toyota doesn't seem to have this figured out. Or maybe they do, but the proper fix isn't worth it.

It's a small comfort knowing that someone else made it to 200K miles when you're sitting on the side of the road with far fewer miles and a blown engine.

 

It sounds like they are replacing all parts that are touched by the oil. The dealer is having to build up the engine, despite the fact that they have 12 complete engines in inventory slated for "recall Trucks". Toyotas thought process doesnt make sense. I have no estimated completion date and i continue to drive a loaner tacoma.

 

Problem is that there are so many recall trucks... and the replacements are behind schedule... that they don't have enough full engine assemblies to also fix the other non-recall failures. How do you like the Tacoma?

 

The Tacoma is too small for my taste and I miss the power of the Tundra. The fit, finish and design are nice.

 

Did I say something that wasn't understood or misunderstood? I meant to say or be inferred from what I posted is that with doing your own maintenence doesn't show up in the computer system or isn't traceable. They toyota or the independent warranty company will have a reason. To deny or delay covering items that they would say you neglected to service the truck.

 

Magnuson–Moss Warranty Act