Watching 1am. Dad's been in surgery since 4pm. Thanks Bill for taking the edge off

@johnfitbyfaithnet

3 жыл бұрын

Peace bro

If I owned a Powerstroke, I'd have Bill do my work for sure. I bet he could put toothpaste back in a tube.

@airhorn2111

6 жыл бұрын

Robert Davis Archoil can put toothpaste back in a tube, then put the tube back in the box, and put the box back on the shelf at the store.

Casting issues...it is what it is. Remember the MD, DC-10 that grenaded the turbine disc on the tail mounted engine and severed the entire hydraulic system causing a very bad day for the souls on that aircraft??? Micro fracture in the titanium during the cool down period after casting at the factory. Lasted Years before it finally failed. This sort of thing happens on rare occasions...If a human made it, it can or will fail.

@281CubicInchesOfFreedom

5 жыл бұрын

Coldsmoke UA232. Glad I’m not the only one who thought of this.

I worked with a guy thay had this same thing happen with about the same amount of miles. 2011 truck bone stock around 60000 miles. Ford investigated and concluded a casting flaw in the crank.

@overzealousmaverik

6 жыл бұрын

Bryan Kerns was it covered under warranty?

@bryankerns7086

6 жыл бұрын

His truck was covered under warranty. This happend in 2012.

@monelfunkawitz3966

6 жыл бұрын

Same thing happened to a friend's truck. Same conclusion. It was also a 2011.

@beezy7412

6 жыл бұрын

I freaking knew it. Damn flaws like that are hard to spot on the production line

@timjenkins6049

6 жыл бұрын

Bryan: So these are cast crankshafts, not forged ?

I have watched many of your videos, enjoyed them all. Very impressed by the way you asked for viewer feedback on this engine failure. You could have just fixed the truck but because you actually care about what you are doing you want to know more. Some excellent feedback in these comments. Keep up the good work.

Hey Bill I have been watching your channels for years and I just seen this video for the first time I just want to say thank you for doing a service to help people out then have spent thousands of dollars on diesel trucks to have nothing but trouble you're a saint and one heck of a diesel mechanic LOL

I had Bill do my truck in 2015. Truck is still running perfectly. Not one single leak or issue. Have about 30k miles on it. I do the recommended maintenance and only use Ford parts. Truck is a gem. Thank you Bill

Both of my neighbors bought 11 model 6.7s and one made it about 20k and broke crank and Ford warranted it for him, the other made it just over 100k and spun front mains and same thing, so idk but there has to be a reason for the early failures like this, I also own a 6.7 but a tad newer 2017 and I tow heavy and run it hard, no issues at all yet, but I'm the only guy to touch my truck too, I'm meticulous, I cut every filter, every time on every thing and inspect, always have. But when I want to really feel my age and drive a man's truck I jump in my 2000 crewcab 6sp 4x4 7.3 powerstroke that I have owned for 16 years and not a single person has touched it but me ! Fully built from the ground up, it is a true work of art ! Btw great job keeping on top of the powerstroke community I love seeing them being repaired instead of being thrown away!

Hey Bill, I work at our family run business and we had a 2011 come in with a broken crankshaft also. It had broke straight down the middle but like you said, there was a decent dark spot along the crack indicating it’s been like that for some time. Located in Canada, this was sometime ago now but just found the video now. Excellent content! 👍🏻👍🏻

Great vids this guy on the videos seems honest and to the point in every vid good job and thank u

In our fleet we had a 2011 with 65k miles do that as well. Broken crank and spun the bearings. Our dealer wanted oil analysis before Ford would warranty it. We do pm for oil @ 200 hrs Ans fuels @400 hrs. Truck now has 110k on it deleted of course. Ours was stuck in regeneration for whatever reason. Thx bill you guys rock.

There is a custom farmer in our area who bought a new F-550 with the early 6.7. and it broke the crankshaft too at low miles. It was still under Ford warranty they put a new engine in for him. He said after the new engine was in it ran way better than the original engine ever did.

My friend had a similar incident with his 2012 6.7. He did however have a fifth wheel that he was towing at the time. He was going onto the freeway when he said the crankshaft broke and sent oil all over the freeway. The truck had 22k miles on it and was covered under warranty.

I love how Ford keeps this guy in business. Lol

@rickycollins4633

4 жыл бұрын

you laugh but I work on cummins too and they just as bad.

@benjaminturpin2749

2 жыл бұрын

@@rickycollins4633 that's bullshit. Cummins go in heavy duty applications. Stfu you know nothing jackwad

2011-2013 had a crank snapping problem, I remember seeing them working at Ford

Bill, I was a diesel mech for the USCG & many diesels we ran had a Harmonic balancer do to the characteristic critical speed hence the vibration you dont feel, sounds like your 6.7 had a catastrophic harmonic speed failure. I have a show room mint 2001 7.3 Excursion that every wants..., thanks for great videos!

Thank you for your 6.7L autopsy. You are 110% correct about the casting flaw. You can see that clearly. You need to save that and show Ford engineers. We may have a recall issue. Ford should pay for that repair. It is very peculiar as you say. Thanks again for your videos.

My 2011 did the same thing at 67,xxx dealer replaced it sad they had seen several do it never had any problems after they put the updated engine in sold it at 240,xxx running strong

A metallurgist would your best bet. I would get the crank analyzed by one for sure, It might also be the only way to figure out why it broke

@digitalrailroader

6 жыл бұрын

wickedxe I agree, a metallurgist is probably the best option to find out why the crank broke; but my opinion is that it was likely a casting flaw, because as bill mentioned, there are telltale signs that point to stress fatigue that aren't present on this crank.

@SledgeHammer43

6 жыл бұрын

wickedxe All he would have to do is send the shavings and the crank to a metallurgist. They would have to check the Alloys and compare to Ford spec. It may have been a flaw in the mixture casting, and harmonic mix. I have been working on engines for 24 years and have only seen it once on a Chevy big block.

@timewa851

6 жыл бұрын

how about Ford saving money on tooling running drill bits too too long? Bad oil drilling hole opening up & now here it sits. Looks like it was just that simple & sad.

@ernestmurphy3898

6 жыл бұрын

wickedxe I would say the same thing looks like 3 said they has similar issues. having the journals polished and etched by a mettalurgist for microstructure analysis may prove Ford Decided to welds some of the 6.7 cranks and decided not to re heat treat. if I am correct weld metal will be on one side of the crank more so than the other due to the heat afected zone. ford may have done this because the had a firing order issue as built and found a quick and easy work around, by cutting and welding, just a guess.

@kleetus92

6 жыл бұрын

Well if it's a worn out drill bit, why is it only on the first journal? CNC machining using the same bit for multiple holes. Would you like to try a different angle to bash Ford on?

a few years ago we had a big rig snap the crankshaft and it still ran it was rebuilt not long before.

One of our ambulances (2012) had same thing happen. They were returning from a rescue cruising 55mph and they said same noise. I advised them to turn around and go to Ford dealership. Ford said they drove it in and it lost all gears. After disassembly they found the broken crankshaft and later they found the flexplate had broke as well which is why they lost transmission. They said it was stress from driving and gave similar quote for new/reman engine.

Im not a power stroke owner but have followed your video because I appreciate your experience and knowledge, its good to hear that you say the 6.7 has been a reliable engine, Ford got a bad rap for the Navistar engines and its real hard to beat the reliability of that Cummins that Dodge uses. That is the ONLY good thing about a Dodge. While you were explaining I was saying to myself to replace the harmonic balancer and flywheel just to be sure. Good to hear you are. I agree since there have not been a string of failures like this that is just a fluke. a casting flaw that escaped the inspectors. I have worked in Aerospace for 32 years and shit happens to the best designed part. Keep up the good work Bill, I sure as hell enjoy what you are doing

Man I love your videos u r really smart when it comes to ford and I like that I have learned a lot from you u r doing a great job just won't to let u no man keep up the good work I build Ford's every day at work and a lot u do has help me

I like the reassurance this just gave me that I did the right thing all these years and kept my 00 7.3. As I have gotten older I hate the noisy thing, but 307,500 miles tells me I did the right thing in popping a new turbo on a few months ago instead of selling it when the turbo failed. I was really leaning towards a 6.7 truck but I have a few family members and friends working at Ford that said don't lol! To date my 7.3 has had three water pumps and a transmission which was my fault. 100HP Program and a 40" gooseneck with anger behind the wheel:) 1 alternator 1 starter at 200+k. Still think the 2015 and up 6.7s are pretty sound motors, but the 2012 and under seem questionable. I left Ford as a tech in 99 so I missed out on the good and the bad inside stuff I used to learn. Thanks Bill. Edit, I am a maintenance junky, but this trucks been to hell and back with me so its been used.

I had a Ford mechanic at a fleet dealer in 2013 tell me that the earlier 6.7s should be avoided if they had under 100,000 miles. He said they had a metallurgy problem that caused spun bearings and sometimes broken cranks. He said it only affected some trucks so if buying a used one buy it with over 100,000 miles on it because the problem always manifests before 100,000 miles. He had two in his shop with the same issue you are seeing.

You said that you have never seen metal break like that, we'll, you haven't worked on enough engines young man, you hit it right on the head while I was typing this, chalk it up as what you already know, a stress in the metal, a flaw in manufacturing, to bad Ford says stick it, in my day they would have taken care of it, heck, I remember being on the heavy duty line in 73 and we had a few hundred of these come thru on the old 390 engine, cleanest brake in the crank you ever seen, wow, it just came to me, the exact same spot you now have. Man, I sure made a lot of money replacing them things back then.

I feel your pain with the Saturday is the only day I can get something done without people asking questions or customers calling.

My truck started running rough... I turned around drove 72 miles home ...put new starter in and all of a sudden a knocking started sounded like top back ...before I could shut it down it stopped and locked up ....now I'm thinking my crankshaft broke but won't know till I tear into it . I'll keep you informed👍👍

There have been similar failures in Corvair Flat 6 engines modified for homebuilt aircraft. What was found was that the fillet radius on the connecting rod journal was out of specification after the crank had been reground. The radius was insufficient and caused a fatigue failure in a similar fashion.

It's a simple problem. The bearings are tangless design, they start to spin and then all hell breaks loose and sometimes the crank breaks. There is nothing actually wrong with the crankshaft but the engine is so powerful that when the front bearing spins and locks down on the shaft, the pistons will continue to turn the rear portion of the shaft and.....snap. I have replaced a ton of these engines because of this.

@blackhatter011

5 жыл бұрын

The 6.7 weighs 1100 lbs. You said you have " replaced a ton of these engines because of this". There is 2200 lbs to a ton so I would say you have replaced 2 engines.

@ozzstars_cars

5 жыл бұрын

@@blackhatter011 actually 1 tin = 2,000 lbs. Close enough.

@FISHH00KS

5 жыл бұрын

Maybe he lives somewhere other than the US where they use a metric ton (2,200 lbs). Personally I would have used the term microgram then I could have said I've replaced hundreds of billions of micrograms of these engines. Sounds better.....

@davidmoore8741

5 жыл бұрын

@@blackhatter011 actually 1 ton is is 2000lb 1000kg is 2200lb so ya. Funny thing is we use chain motors here in the US rated at 1 ton but they r actually 1000kg rated motors. But when u take the brake out they will lift 8000lb+ b4 the case fails. We re-reve them with 2 ton head blocks and 3 ton head blocks. Same motor same chains. Just add length of chain x2 and ÷ by 2 for motor speed.

@krisholden5365

2 жыл бұрын

The fact that the bearing is tang-less is irrelevant. The tang on a bearing is simply for locating it. The “crush” that occurs during installation is what makes it stay put. The tang doesn’t do anything to keep it from spinning.

I'm a machinist and I have worked with a lot of different metals. Casting methods have improved greatly over the years but flaws still happen. It's a pretty clean break. I would lean to a casting flaw

Bill....great clip as always....just an idea, I know that the Duramax had /has issues with broken crankshaft in higher performance applications. The factory firing is 1-2-7-8-4-5-6-3 (odd on passanger side even on driver's side). The fix was a different cam (plus tuning) to change the firing order to 1-5-6-3-4-2-7-8. Not saying ford needs different cams since the 2011 6.7 powerstroke order is 1-3-7-2-6-5-4-8......but maybe an idea since #6-5-4 are right in order and putting stress on the crank in the same place? Far as harmonics go, i have worked on MANY 6.2 and 6.5 GM engines in the HMMWV where the balancer was junk can caused the crank to fail ALWAYS at the 1st crank bearing. Seen this as well on C7 cats, 903 Cummins and several others. When the crank broke on the front, it was almost ALWAYS a bad harmonic balancer and lets face it, we dont look at the balancer very much, and more often than not only when something like this happens. Was there any damage to this guys balancer?

@kleetus92

6 жыл бұрын

Or balancer full of dirt, grease or other material?

My dads 2012 6.7 cab n chassis has about 105k ands it been flawless. At 5k the computer failed and left him on side of highway but he got a free tow and repair. The truck has been home stock, iffy on maintenance and it’s been great

This is actually quite interesting as my cousin by marriage in Mexico works at the plant that builds the 6.7 L and he said that when he first started working there there was a bad batch of sand cores that created the problem

running a high compression gas v12(jag/may heads) this happens from time to time and when the crank fractures it's due to one thing: a casting flaw internally. from what i am looking at in the vid and the customers description that seems to be what happened. b4 a new crank is installed in that block check the alignment. damage could have happened because of the crank and if it has this will happen again.

I have seen this exact type of failure on two different 2012 f250 6.7 oilfield fleet trucks and they were quite abused also had 100k+ miles on them and 3 of our local Ford dealers said it was a flaw in the casting process. But both were pulling very heavy loads when broken. Very strange issue though I have to agree.

The one thing I learned in engineering school is round corners are good. Is there any notable difference in the radius between the bearing journal and counterweight on the broken crank and the new replacement? Sharp corners make for huge stress risers and with the timing gears on that end if the clearance on them isn't just right it could transfer a lot of extra force. Love the videos even as a Dodge guy. 😎

I'm a cnc machinist if I was to guess without seeing it I'd guess porosity in the metal they should use a ultrasonic tester to check it as well as a good magniflux to see cracks.

Aircraft mechanic here. If it simply snapped at idle, not under a load, I would agree that it's simply a bad crank. Seen this before on an aircraft engine that snapped a crank pulled back to idle on a landing approach. Sometimes shit happens. Probably a flaw that simply decided to fail on a cold start. It is odd that there doesn't appear to be any void at the fracture site though. Could use Zy-glow or dye pen it under magnification and see if there's a pattern. (Micro fractures) At least when this happens on a truck, nobody dies. Pilot lost the front of the crank, the prop, stalled the plane, crashed and died. We did find voids at the break though in that failure.

some thoughts: i am sure you will make sure enough oil gets to the bearing so there is no abnormal torque on that end of the crank. If a computer error occurs in the fuel (one cylinder anomolous injection), there could be an out of phase firing in the cylinder pounding the crank. assuming these are not the problem, then the fracture on the metal looks like a brittle heat treat error. you can get the hardness tested on several points around the break to verify if is is too hard (or too soft).

I worked as a Ford diesel tech for 10 years, a snapped 6.7 crank is not common, most common failure as far as engine, is spun bearings and catastrophic failure from the valves. The only tsb's involving internals of the motor is one for damage to glow plug and Ford says the cylinder is trashed, so the motor gets replaced and saves Ford on teardown costs, and one for replacing exhaust valve for misfire or popping in regen. The 6.7 is far more reliable than the 6.4L but I still drive a bulletproof 6.0 and a stock 7.3 with 300k.

I would check the line bore on the crankshaft journals

Sounds like a manufacturing defect on the crank to me, if you find anything out to the contrary let us know please! Thanks for the new content :)

I remember Haliburton had this issue in their fleet in 2011-2012 in the dj basin. They chalked it up to the extreme idle time the trucks were seeing. 2011 should have an hour counter and idle hour counter. Ford started voiding warranties if idle time exceeded 50%. Maybe this could help your quandry...

I've had harmonic balancers and flexplates break cranks. Even a torque converter. Usually the break is close to the problem. My best theory would be the harmonic balancer. I'd take a real close look at the balancer. Then like you said, probably a casting (forging) flaw.

In fact, at my grand father's shop, we replaced one in an old man's truck that was 100% stock and VERY WELL taken care of. It only had like 65 or 75k on it when it split. And it was the same kind of situation as your customer. Idling to warm it up in the morning then a couple mins later the guys that HORRENDOUS banging noise and ran outside to shut it down.... Had to be a bad batch of cranks

I think Ford should offer longer warranties. That's my only problem with their new trucks. Huge fan of their 6.7s

I have seen this many times. I have worked on engines for 50 years. I pulled an engine apart that had the crank dropped on the end from a work bench. It was broke in the main journal just like what you see here. I have pulled 3 other engines apart that had impacts on the crank end. All were the same way. One of them was an old 455 olds wildcat engine. The man hit a piece of firewood dead center on the engine and broke the harmonic balancer. He had another one put back on but it started knocking about 1,000 miles later. Broke crank right at the same main.

Looks like a pretty sharp undercut radius at the ends of the rod journals and possibly a stress riser. There are a lot of inline six-cylinder diesel cranks with undercut rod journal radii and as long as the under cut it smooth and "round" like an inverted fillet, they live forever in heavy-duty diesels. Put a sharp undercut in a high-output light-duty diesel V-8 and it looks like it could be an issue. Could be just a random thing with some cranks getting a slightly sharper or deeper cut or some weren't finished with the right radius, etc. If its the main bearing adjacent to the break that spun my guess is as soon as the crankshaft broke oil pressure at that bearing dropped to nothing or close to it assuming the snapped off rod journal was lubricated from that bearing. The "warming up on a cold morning" thing makes a guy wonder about somebody giving it a sniff of ether on a really cold morning when it should have been plugged in since "will start" and "should be started" at a given temp without being plugged in are two different things. Maybe low batteries (not uncommon with frequent cold-start/insufficient run-time to recharge and high accessory loads during brief running periods (heated seats, blower fans cranked to max, lights turned on etc as soon as the engine is started) could combine with cold-start injection timing/pilot injection to hydraulic a cylinder slightly in a few slow revolutions. If the issue wasn't manufacturing/material-related, it pretty much boils down to either the crankshaft just snapped for no reason or something stopped one or both front pistons during cranking while the others were firing and that caused some sort of shock loading and maybe over a period of time that eventually fatigue-cracked the crank. Good parts don't just break for no reason in my experience and "diesel parts" doesn't automatically guarantee "good parts". Neither does "meticulously maintained" and "excellent maintenance" always equate to "proper operation". Every mechanic occasionally comes across that customer that never misses an oil change and washes/waxes a machine more often than they wash their underwear but put them behind the wheel and they can tear up a anvil in a sandbox with a rubber mallet. You mentioned Amsoil and I know its the be-all/do-all/end-all oil for a lot of guys but I don't know if its DIESEL OIL or not and what kind of "staying power" it has compared to 15W-40 heavy-duty diesel oil and if that could be an issue at startup and cause a spun bearing in the wrong situation or not. A little extra wear on an already compromised crank journal from being the last bearing to get lubricated and/or the most poorly lubricated could possibly cause some oddball failures in a highly-stressed engine like those are. Like I said, the lack of a nice full fillet on a V-8 diesel crank like that makes me a little nervous and undercutting the edges really looks iffy. All it takes is a final polishing/radiusing/heat-treating to be done incorrectly or not at all and a good crank is a ticking time bomb. That's why in the heavy-duty diesel world or at least the parts of it I've been exposed to (ag, construction and railroad locomotives) we've (myself and my employers) stayed miles away from turning cranks undersize. Its too far into a big diesel and labor and time and parts and liability and downtime are too expensive to jack around "repairing" or "remanufacturing" or "rebuilding" a tore up crank. Failure analysis is always a crapshoot when problems aren't fairly obvious and/or the failures are intermittent and rare and "unheard of", but I definitely think you're smart to slap a new balancer on it and I'd give the flex plate a good look if its an auto or the clutch assembly a good look if its a manual trans, too. I'm not a Ford guy so I don't know if 6.7s even come with/came with manuals but either way check downstream of the engine as far as you can to make sure nothing else was the perpetrator or victim of this failure. My gut instinct is crankshaft material/manufacturing first and honestly given what you've know and have been told, that's the only cause you can give the customer.

Watched a ford tech vid a yr back. He was swapping in a new 6.7 on a service truck. He said that they had done several of these due to snapped cranks. He said they were all on the cab and chassis trucks though.

It happened during start up and was idling, that says there was a low pressure, no pressure situation, that caused that.

Ford had a machining problem in 2011 with the main caps. It would cause the caps to twist slightly and bind thus causing the crank to break.

I've heard of these stories about these yammaha outboard engines where you have to replace the flywheel every 50 engine hours or else the harmonic balancer goes bad and breaks the crank.

@FR7IMI

6 жыл бұрын

Just on the 350's.. It's every 80 hours that are within the 3800-4200 rpm range.

@kleetus92

6 жыл бұрын

recall or class action suite.

@BrianSmith-lo3mj

6 жыл бұрын

@ kleetus92 ... Exactly, I'm glad someone on here said it before me.

@powerstrokehelp I've had to replace a bunch of duramax engines for the EXACT same thing, broke exact same journal, spun same bearing, ran, stock truck. never could figure out why other than speculing about bad balancers. got photos if you don't believe!

I'm in the manufacturing flaw group of thought here, thats got to be what it is.

Check the Line Boring for the crank to see if its aligned I came across a few engines that broke cranks because of the bores being a bit off Cummins N14, a few ford blocks and other engines Its something to check.... I seen some cams snap from misaligned bores too. From the misalignment it puts a little wiggle in the shaft making it fatigue and snap in a nice clean break Typical metal fatigue

Seen a 6.7 with a broke crank as Russ Milne Ford here in Detroit. The tech said it is a more common issue than you would think.

First time visiting your channel, you are a smart man. I agree with you on either harmonics and/or bad crank forging. 35 year machinist and machine shop owner here. I’ll throw in one more possibility, how is the oil hole drilled, is it too close to the rod radius which is the weakest part of the crank?

I'm a planer man and Harmonics can be a gremlin that almost always goes to mounting or stress. It always ends up in the finish product.

It is actually NOT a "Casting" Flaw. That is a forged steel crank, not cast or nodular iron. Steel 90 Degree V-8 Cranks are forged as a flat plane and then literally twisted into final shape, before grinding to size. If you look at a forged crank, you will see a wide parting line that results from the two parts of the dies that make the raw part. A cast crank has a parting line that travels generally straight down the center of the crank. Cast cranks are cast into their final shape, then ground. No twisting to attain final shape. Cast cranks are cheaper to manufacture and slightly weaker. After initial flat rough forging, the blank is trimmed of flash and crank is then actually twisted, while red hot, to form the 90 degree bends, this is how the forging line comes to be in line with the center of each rod journal. That is not to say that the manufacturing process did not cause the failure. Another possibility is an improperly finished radius where the rod journal transitions into the crank web. I have seen these types of breaks on many reground cranks that did not have a proper radius ground back into the journal. I also would agree with the original idea of a Harmonic issue (imbalance), which many times will not manifest itself until the crank breaks from the stresses of constant but imperceptible vibration. Could also be a combination of more than one of three factors.

@thegreenerthemeaner

6 жыл бұрын

Michael Lynch You gave the answer I was about to give. I would also add that from the little I can see of the small portion, there is some shiney surface near the fillet radius where the crank pin joins the main journal, the absolute weakest point of any crankshaft. The shinning would indicate movement. Also the timing gears may have worn to inconsistent tolerances causing a slight but brief flex harmonic that wouldn't vibrate to the casual observer, but would require sine wave equipment to detect and a comparison to healthy consistent wear engines. No one will go to those lengths on an internal combustion engine as a final check, but they do use such equipment to monitor electric generators in water and steam power to track potential problems.

@williamlewis7846

6 жыл бұрын

I used to regrind cranks, there is little margin of error in the Radius. Even concentic lines from an improperly dressed wheel can cause fractures.

@Nonplused

6 жыл бұрын

Could there not have also been a forging error say if part of the steel wasn't hot enough when it was forged and thus a small crack could have been formed? Even a tiny crack in such a case could propagate over time. Although I find it strange that the owner says it broke idling in the driveway and not under load, no matter what caused it. I blew up a Mercury outboard under fairly normal operating conditions once and the mechanic blamed it on manufacturing. Unfortunately that was well out of warranty too. (Spun a bearing which wrecked the crank and bottom 2 cylinders. Not cheep. I was 1/3 of the way to a new engine by the time it was running again. PS not a big fan of Mercs anymore but I don't have money to replace it for the amount I use it.)

@chrisgorgas1929

6 жыл бұрын

I worked in a large forge shop, sometimes you get sand in the steel forging and don't catch it. I don't know where ford is getting their steel from.

Wow. Haven't heard of that before. Crazy it was a stock truck as well. I mean, initially I would write it off as a production flaw. But, not a whole lot of evidence to support. How did the balancer look?

My ISX CUMMINS in my Kenworth did the same thing snapped right in to. Thank god it was under warranty 35000 for a new motor. Kenworth said it was a casting flaw.

I have only seen cranks break like that from either extreme abuse or way out of balance. Maybe send the balancer and the fly wheel too the machine shop and have them compare them too new. As too your old teacher and 100 hour weeks, he was 100% correct. I own a small construction company, 17 employees all of them on site today, waiting for 7 am so we can start making noise.

@gr8guitarplayer

5 жыл бұрын

So basically what you're saying, is you, as the owner, have to put in 2.5x's as many hours as your employees in order to keep up with them: Keep enough work laid out in front of them. It's not true. I too am a small construction company owner, but with half as many employees. I've had them all on the same job a few times (when the next jobs just didn't break at the right time.) I can't stay ahead of that many guys unless I have a couple whom I start DELEGATING tasks to that I normally do. That is the key. As you grow in number of guys, you gradually train others to take over your tasks. That's why construction companies have foremen, superintendents, estimators, bookkeepers, sales people, project managers. If all you have are Indians, you'll just keep adding more hours to your own work week, or you'll start making the right ones Chiefs.

reminds me of my old 6.5 harmonic went bad and snaped like that

i have heard the 11's and only the 11's are known for spinning bearings, but were updated in 12. havent seen it first hand

When the part was poured there was a interuption in the flow of liquid metal causing a temp differential. Caused a weak spot.

No Industrial Diesel Psychotic Tune like that ole tug of war 6.0L video? Still one of my favorites.

Ive heard of this happening. Broken crank in 6.7s and still runs. Had an f550 come in at my old job for a spun bearing, and another coworker said he's seen em break cranks.

Classic "We won't know in our lifetime will we?"

Is there any odd wear on the timing gears? and how did the top of the front two pistons look like? maybe a small case of hydro lock from a leaky injector?

My father's truck did the same thing. He had around 37,000 miles and it broke closer to the harmonic balancer. It's a 13 f350 truck. He pulled out of a stop sign and it locked up instant.

sometimes things just break...... thats why roller coasters are exciting i guess.... while in the navy i watched a huge thick solid steel pelican hook for the ships anchor chain snap like a twig..... nothing lasts forever...

Folgers can is a must have in any shop.

Would be interesting to check the line-bore of the block. If they somehow got the bearing stagger wrong (plus and minus on opposite sides from what was measured) the crank would run tight on one side which could stress it under load. Given enough time the crank fatigues and eventually fails from the minute bending. Does it have select fit bearings? Bet it does.

A Ford tech on the east coast who has a KZread channel has replaced a couple two or three 6.7 powerstrokes due to broken cranks. All have been narrow frame cab and chassis units. Not pickups.

I saw a 5.0 engine that was ran on nitrous at one time, break the crank in that same location later. I'm sure it was due to hitting a high RPM. So, the nitrous weakened the crank and caused the crack, but the high RPM caused the failure.

A friend of mine has a 6.7 in a roll back and it has broken the crank just like this. I'm not 100% sure but i believe ford has a TSB for this problem.

At the ford dealer I work at we've seen two 6.7's with broken cranks. Crazy

@carl2591

6 жыл бұрын

you remember what year and how many miles on them..??

Looks like a Flaw in the Journal radius, Ive seen many race cranks do this . The grinding wheel cuts a small groove in the radius , thus setting up a Stress riser .

I had a crank failure on a 5.0L small block chevy used in a marine application. Volvo Penta SX, 5.0L. I never really had an exact cause but I came to pretty much the same conclusion. The only difference was I switched to a 17" prop vs the 19", however it was a Volvo Penta brand prop and according to my own research and the dealer I bought it from, I should have been in the correct RPM range for the engine. I exceeded 5000 RPM on several occasions, however, never for a long period of time. The bearings to either side of the break in the crank had failed. Again, not sure of the exact time line as to what failed first. I have pictures if you would like me to send them to you.

My thoughts are casting flaw, or heat treating issue (if they do that) or harmonics.. other thought would be a block that was not line bored right..

And the crank was the problem. Seen it a couple times. Our customers always say it happens when they first crank in the morning. All 11 models

That guy's incredible NE

Not on a 6.7 but on a 6.4 bucket truck I put 3 long blocks in it in 22k miles truck only had 68k. Found the torque converter to be out of balance before I put the 3rd one in it. Changed the converter and 100k later it’s still running.

Late to the party but from the section of the crank still in the block the fracture is satiny and all scalloped out, so its probably fatigue failure. My guess would be just a faulty crank with some sort of defect or inclusion. Edit: 5:38 you can see the scalloping that's characteristic of fatigue failure. If the oil was kept clean, you may not have enough dirt to migrate into the crack and color it.

Have you considered sending the harmonic balance back to the manufacture?

I seen two crankshafts break exactly the same way I'm going to go with a casting flaw

I would set up a harmonic frequency detector with a scope recorder, let the engine run at varying speeds, and see if you can find any dissonances.

I was wondering if magna-fluxing the crankshaft show any more cracks or metal failures? Or x-raying the crankshaft the only way to know if there is metal failures in the structure?

Early model 6.7 had a little trouble with cranks and turbos

My vote is bad crank from factory. Harmonic would be felt/heard. Rare, yes, but I think bad crank casting.

That looks to have failed in the exact same spot and in the same way as a GM 6.5 diesel, though the cause of a crank failure in a 6.5 is almost always either a bad harmonic balancer or a bad dual mass flywheel. And like Bill said, normally you'd feel a harmonic vibration. When the balancer failed on my 6.5 it felt like it was down one cylinder at idle.

Yes... But not with crank. I seen one with only 4k on it and it was a 2011. It drop a valve. I have never heard of one doing it since. I was working at a Ford dealership at that time

Balancing, casting flaw, or a sonic boom or noise. I seen that back in 2000 with a big bore Cummins at the dealership. I would also inspect it four beach marks at the break. You can also get it sonically check to see if other areas of that crank it week. I'm just saying. Bill, let us know what you find.

It broke right at the radial fillet. So it may have been a machining error. Did you take the time to check the alignment of the mains?

Ford must've used a Duramax crank in this one. Damn things snap cranks like it's the cool thing to do. It was a problem from the first generation LB7 engine all the way up to the outgoing LML. We'll see if the L5P crank is any better. I have an 06 GMC 2500 with an LBZ Duramax that has 308k miles on it, but the possibility of it snapping the crank or cracking a piston is always a thought in the back of my head. Duramax shortblocks are extremely fragile. To see a Power Stroke, let alone a 6.7 with a broken crank is very surprising.

Id be interested to know what it was, ive heard of this before in those trucks a few times, but i could only guess that its either a casting failure, which since the oil gallery in the crank weakened that piece and time took over when it broke. Just looking at the grain structure makes it look stressed when it pulled it apart.

Cylinder #1 is still on the right side front or passenger side front on the 6.7 powerstroke.

I've had a truck do this, one main bearing spun when the truck was passing someone on the freeway and broke the crank. The main and rod bearings don't have any retainers so they spin easier. I have a 2016 with 15000 miles that spun a main. I'm waiting on the short block so I can put it back together.

I saw a crank break like that on a 1979 C10 Suburban that had a 454 from the factory 30 years ago. He pulled a travel trailer, but he babied it AND the speed limits were still 55 max. We just figured it was a bad crank from the factory. It didn't trash the engine, in fact, we put another crank and fresh bearings into it. This was 1985-86???