@1LtCAP and other mechanics, I pose the question to you.  2016 Ford Explorer with EcoBoost motor, 75K miles, original owner.

Explorer Flywheel.pdf

It’s not a manufacturing defect.... 

4 minutes ago, Zeke said:

It’s not a manufacturing defect.... 

So shit breaks perfectly square like that?

Just now, CMJeepster said:

So shit breaks perfectly square like that?

Well you asked 

Is that cast metal? For a flywheel??

8 minutes ago, Displaced Texan said:

Is that cast metal? For a flywheel??

Flywheels are usually nodular cast then machined.  Strength?   That's the same manufacturing technology Ruger uses for frames and crankshafts in engines.

 

I should have clarified a bit more. I’m aware they use cast iron for crankshafts. Maybe it’s just the way the pic is taken, but that looks like cast aluminum...and poorly cast at that. 
 

Again, may be a trick of the light. However, that should not fail in that manner. 

Maybe the lockup converter locked up.  

1 hour ago, CMJeepster said:

@1LtCAP and other mechanics, I pose the question to you.  2016 Ford Explorer with EcoBoost motor, 75K miles, original owner.

Explorer Flywheel.pdf 172.4 kB · 6 downloads

@1LtCAP

Due to the clean rectilinear seems of the failure, I would speculate that some sort of massive point force was applied uniformly and perpendicularly around the outside edges, while the casting was fastened tightly to its adjacent member with six bolts, causing the metal to break as neatly as it did.  Also, was it extremely heated at the point of failure?  
Can you tell us what the cause was?

AVB-AMG

I've seen plenty of flexplates crack, but usually at much higher mileages.  That's where all the stress is concentrated when the transmission shifts and when the torque converter locks and unlocks.  Plus, if the trans input is not exactly in line with the engine crank (tolerances there are in the .00x range) then it happens.  

Quote

 

 

‘ Crank walk’ can cause odd flywheel failures, but I’ve never seen that one. Although I don’t tear apart many engines these days. 

35 minutes ago, AVB-AMG said:

@1LtCAP

Due to the clean rectilinear seems of the failure, I would speculate that some sort of massive point force was applied uniformly and perpendicularly around the outside edges, while the casting was fastened tightly to its adjacent member with six bolts, causing the metal to break as neatly as it did.  Also, was it extremely heated at the point of failure?  
Can you tell us what the cause was?

AVB-AMG

No clue.  Neither one of us drives that vehicle like it's a rented mule.

http://www.agcoauto.com/content/news/p2_articleid/220

Could that have failed die to being over torqued?

 

I would say it might have had some kind of vibration ( balance )  issue

Take the parking brake off dude!

just a guess

  did you take it to Ford or other and what do they say?  

Well it’s a Ford so.

5 hours ago, Displaced Texan said:

‘ Crank walk’ can cause odd flywheel failures, but I’ve never seen that one. Although I don’t tear apart many engines these days. 

6 hours ago, Displaced Texan said:

‘ Crank walk’ can cause odd flywheel failures, but I’ve never seen that one. Although I don’t tear apart many engines these days. 

Sometimes I pet my crank, but I've never had to take it for a walk. Am I doing it wrong?

48 minutes ago, Handyman said:

Sometimes I pet my crank, but I've never had to take it for a walk. Am I doing it wrong?

Dude, please, leash your crank. 

Looking at it.  Its apparent.  The techs tried to cut down on metal.  Those cut outs are too close to the nuts.   Definitely a design error. 

Looking at it.  Its apparent.  The techs tried to cut down on metal.  Those cut outs are too close to the nuts.   Definitely a design error. Yo.  Keep the part.  Id like to come over and see it for myself

This is why I bailed on Ford years ago. I had an engine just about fall out of an escort. The two main bolts sheared. I had the extended warranty, Ford did not cover it. They agreed it was a defect, but the warranty covered the engine mount and not the bolts in the block. They also denied the appeal, the bolt part numbers were not covered.  Seems nothing has changed since then. Glad I didn’t go for that F150, don’t they have this same engine. 

I suspect a fatigue failure from thousands and thousands of cycles of flexing, instead of a single event.  A single event would have resulted in something being bent - maybe also cracked, but definitely bent.

And, from the location of the cracks, the flexing was in the direction of the axis - like when the bottom of an oil can is pressed in and out - as if the transmission and engine were moving toward and away from each other. 

This part is speculation since I don't know much about transmissions:  I don't know if it's possible that the transmission input shaft was moving forward and backward, maybe as the transmission was shifting?  A tiny bit of movement can result in fatigue failures if it happens enough times.

14 hours ago, FXDX said:

  did you take it to Ford or other and what do they say?  

All work on the vehicle has been performed by the original dealer.  We've been treated well by them over the years.  It's Ford corporate that my wife is on the war path with right now.

12 hours ago, Redlines said:

Well it’s a Ford so.

Our 2006 Explorer went 220k miles with a steering rack replacement being the only non-maintenance item that needed professional attention.

9 hours ago, Golf battery said:

Looking at it.  Its apparent.  The techs tried to cut down on metal.  Those cut outs are too close to the nuts.   Definitely a design error. Yo.  Keep the part.  Id like to come over and see it for myself

Feel free.  It's still up at Ditschman.  She's been in a loaner since Friday when the transmission fluid pump "accidently" decided to go.  Tack on $1,700 to the bill.

44 minutes ago, maintenanceguy said:

I suspect a fatigue failure from thousands and thousands of cycles of flexing, instead of a single event.  A single event would have resulted in something being bent - maybe also cracked, but definitely bent.

And, from the location of the cracks, the flexing was in the direction of the axis - like when the bottom of an oil can is pressed in and out - as if the transmission and engine were moving toward and away from each other. 

This part is speculation since I don't know much about transmissions:  I don't know if it's possible that the transmission input shaft was moving forward and backward, maybe as the transmission was shifting?  A tiny bit of movement can result in fatigue failures if it happens enough times.

Whatever the case may be, we're gonna be in the market for a new vehicle for her.  She's done with Ford for now.  Hell, she even wants me to sell my stock and cancel my Mustang Club of America membership!

I know what @gleninjersey would recommend as a replacement...

23 minutes ago, CMJeepster said:

Hell, she even wants me to cancel my Mustang Club of America membership!

@CMJeepster:

Woah.....  Hold on there!  Let’s not get carried away.....

IMHO, the MCA has some of the most passionate and interesting automobile aficionados in American car culture, centering around an important iconic vehicle.  Don’t sour on one of the most active car clubs and its enthusiastic members.

AVB-AMG

P.S. - You and your wife may want to consider test driving a new or used BMW X5, as a possible replacement for your Ford Explorer....