Crank hub issue; UPDATES* ?

[The Choosey begger]

Originally Posted by FC4

Can always email these people so it's on their radar...

ludwig.willisch@bmwgroup.com - President and CEO

rebecca.kiehne@bmwna.com - Product and Technical Communications Spokesperson, BMW of North America

alexander.schmuck@bmwna.com - Product & Technology Communications Manager at BMW of North America

hector.arellano-belloc@bmwna.com - BMW Product and Technology Spokesperson at BMW of North America

gabriel.dunn@bmwna.com - Media Communications Manager. Direct phone:

ralph.huber@bmwna.com - Chief of Technology Communication

kai.lichte@bmwgroup.com - Product Communications Manager

dirk.arnold@bmwgroup.com - Vice President Product, Technology and Sports Communications, Press and PR Events

bill.mcandrews@bmw.de - Vice President Communications Strategy, Corporate Communications, BMW Group

jan-christiaan.koenders@bmw.de - Executive Vice President, Sales and Operations

That's absurd!

What are you going to tell these guys? Hey i wanna mod my engine to put down over 500WHP without worrying about spinning the crank hub.

In stock form the S55 is pretty reliable, of course a few engines will experience catastrophic engine failures, nothing out of the ordinary compared to other manufacturers.

BMW expects you to keep your engine stock and they'll be more than happy to replace your engine under warranty worst case scenario.

[M4 CSL]

I have a question. How many hubs that slipped, and were repaired by BMW, did it a second time? To my knowledge, NONE.

"IF" and I say "IF" there are none, do you think BMW knows something the aftermarket world doesn't?

Mine was fixed by BMW and hasn't been a problem since. (Touch Wood).

I remember hearing of quite a few others that got their's replaced under warranty and yet I have not heard anything from those people again.

It seems that the only ones that have failed again, are ones that have been repaired aftermarket, outside of BMW. So my question is, I wonder/Hope does BMW know far more than they let on, and have they fixed the problem?

I would like people who had their's fixed by BMW to chime in. I know the first thing they do is upgrade your software. But who knows what else they do?

Maybe nothing, might just be luck. . But would be interesting to know if a dealer fixed one re-occurred or not.

[Sleeper]

Originally Posted by M4 CSL

I have a question. How many hubs that slipped, and were repaired by BMW, did it a second time? To my knowledge, NONE.

"IF" and I say "IF" there are none, do you think BMW knows something the aftermarket world doesn't?

Mine was fixed by BMW and hasn't been a problem since. (Touch Wood).

I remember hearing of quite a few others that got their's replaced under warranty and yet I have not heard anything from those people again.

It seems that the only ones that have failed again, are ones that have been repaired aftermarket, outside of BMW. So my question is, I wonder/Hope does BMW know far more than they let on, and have they fixed the problem?

I would like people who had their's fixed by BMW to chime in. I know the first thing they do is upgrade your software. But who knows what else they do?

Maybe nothing, might just be luck. . But would be interesting to know if a dealer fixed one re-occurred or not.

The sample size of all forum users (specific to the F8x sub forum) is too small, and even smaller when you're trying to get info on this same sub forum from those who have had the problem. The data would be irrelevant. Interesting, but irrelevant.

[BMW M4 PWR]

Lol! You guys crack me up... "I was sittin on my toliet shittin' last night after eating a vicious serving of chipotle and I coulda SWORE I felt my crank hub slip right there!"😂😂 Wtf man...

On a serious note though, let's find out a solution to this so the big HP and fast 1/4 & 1/2 mile track times can commence and show what this platform is really capable of** The bootmod3 flashing tuner 'should' be available soon, along with a couple solid fueling solutions, everything's beginning to be in place for easy BIG HP... as long as this F-in crank hub is addressed. I mean in the scope of all things BMW coulda f*cked up on the F8X it being the *crank hub* is a blessing!🙌 lol

[BMW M4 PWR]

Originally Posted by Railgun

<10.

(read:less than anyone thinks)

You think less than 10 ever failed bc of this issue?

I would think we're already much higher than that but the "internet" tends to make things appear larger than they really are

[///M4RINE]

Originally Posted by EBM4

...I just upgraded my turbos but if this gets worse I'm bailing on this platform also. Many guys will not worth the headache we can go by 997 turbos etc.

As someone who owned a 997TT, I can tell you that the grass isn't greener. Ditching the F8X platform over this issue may be overreacting (especially when it's still under warranty).

[minn19]

Originally Posted by Railgun

Point being, less than warrants sending an email to the CEO.

Or needlessly trying to scare the shit out of every M3/4 owner out there. Who would do such a thing?

[JoeFromPA]

I've followed this for as long as possible and have tried to sum up the current knowledge at different stages. I'm not an engine builder/expert, I'm a researcher who typically is good at summarizing the current state of research.

There have been ~10-15 identified stock crank hubs that have slipped in the >2 years and over 40,000 s55s on the road. They have almost all slipped on DCT cars and most have been modified. The number of slipped crank hubs has, oddly, not increased linearly with time/production - in fact if anything we've seen a decrease in reported cases over the past 6 months.

While it appears to happen to both modified and unmodified cars, the reason why is not understand AT ALL. There is a strong case to be made that:

1. BMW designed the crank hub to produce minor slip in certain circumstances on the s55, for reasons we can guess at.

2. The crank hub's load DOES NOT increase with engine output. Whether you make stock power or 700whp, the crank hub is just spinning a chain. It's load does not increase with more power.

It is unknown why the crank hub spins in some circumstances. Some people blame design, which is fair, but why is it so rare and inconsistent. If it is a function of kickdown, why doesn't it happen reliably and in more escalating numbers? The incidence of crank hub spin/failure is not consistent with a design problem.

Is this something you should be worried about right now?

In my opinion, no. We are talking about something that has probably impacted roughly .05% of S55s produced to date (which would assume ~20) and has not been increasing in regularity. Several reported cases have been confounded by having one member have repeated crank hub failures due to improper installation of a new/aftermarket model, or the aftermarket model itself failing.

[The Choosey begger]

Originally Posted by JoeFromPA

I've followed this for as long as possible and have tried to sum up the current knowledge at different stages. I'm not an engine builder/expert, I'm a researcher who typically is good at summarizing the current state of research.

There have been ~10-15 identified stock crank hubs that have slipped in the >2 years and over 40,000 s55s on the road. They have almost all slipped on DCT cars and most have been modified. The number of slipped crank hubs has, oddly, not increased linearly with time/production - in fact if anything we've seen a decrease in reported cases over the past 6 months.

While it appears to happen to both modified and unmodified cars, the reason why is not understand AT ALL. There is a strong case to be made that:

1. BMW designed the crank hub to produce minor slip in certain circumstances on the s55, for reasons we can guess at.

2. The crank hub's load DOES NOT increase with engine output. Whether you make stock power or 700whp, the crank hub is just spinning a chain. It's load does not increase with more power.

It is unknown why the crank hub spins in some circumstances. Some people blame design, which is fair, but why is it so rare and inconsistent. If it is a function of kickdown, why doesn't it happen reliably and in more escalating numbers? The incidence of crank hub spin/failure is not consistent with a design problem.

Is this something you should be worried about right now?

In my opinion, no. We are talking about something that has probably impacted roughly .05% of S55s produced to date (which would assume ~20) and has not been increasing in regularity. Several reported cases have been confounded by having one member have repeated crank hub failures due to improper installation of a new/aftermarket model, or the aftermarket model itself failing.

I'm gonna guess the one member's engine with repeated crank hub failures was north of 500WHP and the reapaired stock engines didn't see repeated failures.

[JoeFromPA]

Originally Posted by anglo

I'm gonna guess the one member's engine with repeated crank hub failures was north of 500WHP and the reapaired stock engines didn't see repeated failures.

Yes, and he has at various times accredited the various post-stock failures to improper installation of a new crank hub (i.e. torquing) and part design of a new aftermarket crank hub failing.

I'm unaware of any repaired stock engines seeing a repeat failure.

[s2k750]

Originally Posted by JoeFromPA

Yes, and he has at various times accredited the various post-stock failures to improper installation of a new crank hub (i.e. torquing) and part design of a new aftermarket crank hub failing.

I'm unaware of any repaired stock engines seeing a repeat failure.

Keep posting... You're making me want to spend money on mods :thump:


I wish i never joined this forum, my car would be 600whp. lol

[M4 CSL]

Originally Posted by JoeFromPA

I'm unaware of any repaired stock engines seeing a repeat failure.

Yes, this was my point earlier. IF this is the case, and so far we believe it to be, then does BMW know how to fix it?

[te37]

Originally Posted by JoeFromPA

I've followed this for as long as possible and have tried to sum up the current knowledge at different stages. I'm not an engine builder/expert, I'm a researcher who typically is good at summarizing the current state of research.

There have been ~10-15 identified stock crank hubs that have slipped in the >2 years and over 40,000 s55s on the road. They have almost all slipped on DCT cars and most have been modified. The number of slipped crank hubs has, oddly, not increased linearly with time/production - in fact if anything we've seen a decrease in reported cases over the past 6 months.

While it appears to happen to both modified and unmodified cars, the reason why is not understand AT ALL. There is a strong case to be made that:

1. BMW designed the crank hub to produce minor slip in certain circumstances on the s55, for reasons we can guess at.

2. The crank hub's load DOES NOT increase with engine output. Whether you make stock power or 700whp, the crank hub is just spinning a chain. It's load does not increase with more power.

It is unknown why the crank hub spins in some circumstances. Some people blame design, which is fair, but why is it so rare and inconsistent. If it is a function of kickdown, why doesn't it happen reliably and in more escalating numbers? The incidence of crank hub spin/failure is not consistent with a design problem.

Is this something you should be worried about right now?

In my opinion, no. We are talking about something that has probably impacted roughly .05% of S55s produced to date (which would assume ~20) and has not been increasing in regularity. Several reported cases have been confounded by having one member have repeated crank hub failures due to improper installation of a new/aftermarket model, or the aftermarket model itself failing.

Correct, BUT the engine is progressing through the rev range significantly faster than a stock car, I.E. things are moving faster more quickly which in turn means more force.

[F82_M4]

I had my crank hub issue sorted on warranty on stock m4, the bolts have melted !

[BMW M4 PWR]

Originally Posted by F82_M4

I had my crank hub issue sorted on warranty on stock m4, the bolts have melted !

What!? Say again, melted bolts!? lol ...stock��?

[CaryTheLabelGuy]

Originally Posted by te37

Correct, BUT the engine is progressing through the rev range significantly faster than a stock car, I.E. things are moving faster more quickly which in turn means more force.

Not nessecarily any faster than a free-rev.

[BMW M4 PWR]

Originally Posted by CaryTheLabelGuy

Not nessecarily any faster than a free-rev.

True that^^



Well guys, after exhaustive research and LOT's of phone calls I've identified a couple of high HP guys (700hp) that are still in the testing-phase of their crank hub issue solution. Unfortunately I can't speak of whom they are and what specifically their solution is on a public forum out of their wishes until they're done with their testing... I can say apprehensively that so far so good👍 Point being, there are people working on this right now*

[SYT_Shadow]

Originally Posted by ///M4RINE

As someone who owned a 997TT, I can tell you that the grass isn't greener. Ditching the F8X platform over this issue may be overreacting (especially when it's still under warranty).

I laugh my ass off when some genius gets upset by a tiny percentage of failure in an M car and says they want to move to Pcars. The expectation that Pcars are more reliable than M cars is laughable at best.

Someone else mentioned Tesla and Faraday. I hope they were kidding. Those cars are not even beta. A mag has a long term test one that has already had the entire drive train replaced - twice!
To think they would be more reliable than one of the F8x cars makes me worry about the future of humanity

[JoeFromPA]

Originally Posted by te37

Correct, BUT the engine is progressing through the rev range significantly faster than a stock car, I.E. things are moving faster more quickly which in turn means more force.

There is no in-gear power application that spins your hub faster than simply sitting there in neutral and going WOT.

Therefore, whether stock or 1000hp, no amount of power forces the crank hub to accelerate more quickly than free-revving in neutral.

The flip side of that is the DCT. Nothing forces your crank hub to change speeds faster than a DCT kickdown either. And that's regardless of power.

There are numerous problems with the DCT kickdown theory though, primarily being that if DCT kickdown was the root issue then you should be able to institute a timing problem/crank hub spin at will or at least with repeated max kickdowns. But that doesn't happen or at least no one has shown they can cause a crank hub spin on demand.

[BMW M4 PWR]

Originally Posted by JoeFromPA

...if DCT kickdown was the root issue then you should be able to institute a timing problem/crank hub spin at will or at least with repeated max kickdowns. But that doesn't happen or at least no one has shown they can cause a crank hub spin on demand.

Has anyone actually TRIED this? I don't think anyone would TBH... and to date, there has been virtually no failures to speak of on the 6-spd MT's that wasn't a result of a misshift. <--That in itself is a huge observation.


Pure turbos is still running their factory stock crank hub on their 700whp 6-spd MT that they race regularly and its holding up if I'm not mistaken?

[proTUNING Freaks]

Originally Posted by JoeFromPA

There is no in-gear power application that spins your hub faster than simply sitting there in neutral and going WOT.

Therefore, whether stock or 1000hp, no amount of power forces the crank hub to accelerate more quickly than free-revving in neutral.

The flip side of that is the DCT. Nothing forces your crank hub to change speeds faster than a DCT kickdown either. And that's regardless of power.

There are numerous problems with the DCT kickdown theory though, primarily being that if DCT kickdown was the root issue then you should be able to institute a timing problem/crank hub spin at will or at least with repeated max kickdowns. But that doesn't happen or at least no one has shown they can cause a crank hub spin on demand.

Great points. We're adding an item on the list to look into adding a kickdown disable feature for those suspecting this to cause the hub spinning issue.

[M4 CSL]

Originally Posted by CaryTheLabelGuy

Not nessecarily any faster than a free-rev.

Interesting, how about sitting on a Dyno?

I wonder what the correlation between Spun hub cranks and guys that have had multiple Dyno's?

I don't believe it's a kick down issue at all. It's a fuel saving, put the car in 7th gear at low speed issue. If you were in a manual, the car would be coughing , spluttering and stalling and even kangarooing.

Yet these DCT's are laboring around in top gear. I don't use auto mode anymore. When I watch the gear changes, the car always suggests at least 2 gears higher than what I am in. It's ridiculous. To save a few sips of fuel.

I have a friend who drives the crap out of his car, to the point of abuse. He has a jb4. Whilst he is starting to have clutch issues, he has never spun his hub.

He never uses 7th gear. He is always wringing the things neck and revving it in lower gears. That's pretty much how I drove my previous manual M cars, without issue. I think it's a silly issue that has arrived with the quest to have more gears, and fuel saving measures.

Can someone reprogram the car, to not up shift automatically unless you are above 4,000 rpm? Or some way of preventing it from being 2 gears higher than it should?