Spun Crank Hub @ 2300 miles.

[chmura]

Originally Posted by Tommy L Garage

How much is this fix if one is out of warranty?
Do people typically find a used motor or are we talking about a rebuild?

Either way...what $ are we talking about here to fix?

What I want to know is how to fix the problem and install the fixed part before it becomes a problem?

There have been a lot of 'fixes' but none worked supposedly.

This is the ultimate fix.

These seems like isolated issues. I just got back from M track days last Saturday. And people were absolutely thrashing the M3/M4's on the track. bouncing off rev limiters for long periods of time (Noobies did not know they were in manual mode), aggressive kick downs, etc. All cars were FINE!

Like the OP said these might be from inadequately torquing them.

[NoMoreAudi]

I never broke in my engine and sent it from 10 miles on the odometer. Highest rev downshifts (2nd to 1st gear going 20+ mph), redlining when cold, WOT in 7th gear when going only 65mph. We may hear about SCH cases on the forums but the % of owners who are actually on the forums is very small compared to the number of F8x out there...

For all we know, the failure rate could be 1 out of every 15,000 cars produced...

[Justin.AutoTalent]

Originally Posted by moonshine89

Which one?

Originally Posted by Richy Rich

Not sure, Justin.AutoTalent will know.

Vargas looks the best especially if there is no modification required. Just waiting for the part to come in

[minn19]

Originally Posted by NickyC

I've read everything from a few grand if you're lucky to an entire rebuild/new engine (+$25k). Lots of luck appears to be involved in all aspects of this saga.

Due to these issues, this will be the first car I've had in the past 20 years I won't be modifying engine/intake/exhaust wise. I'll be purchasing the extended warranty from BMW when my warranty runs out in June of next year. I love the car, and it's fast enough as it is. It's quite a bummer however as I don't want to screw with anything, not intakes, exhaust, etc. Nothing that BMW could use against me if something were to go wrong.

I here yah, but as long as you don't mess with the downpipes/headers you should be fine modding the rest of the exhaust. Intake I'm not sure of, but I'd doubt they would void a warranty based on that. But, you never know.

[f80er]

Where is OP?

[BAN_M2C]

Originally Posted by f80er

Where is OP?

Exactly..

Update?! Was it resolved?

[Lerxst M4]

Bump -

Mork calling OP, come in OP. Any updates, sir?

[MR RIZK]

Nanu Nanu

[PacificBimmer]

My 2019 M4 has 2100 miles on it and I am experiencing the same issues (VANOS codes, long crank, etc) after WOT run at high RPM. Going to start some further diagnostics and bring into the dealer.. will start a thread with the specs.

[Graves]

I'm about to crack 10k miles and wanna put a BM3 Stage 1 on it. I have dogged this car out. 170+mph sustained runs on the autobahn, zero issues. Not sure if I should worry about it or leave it stock.

[deeldoo]

Originally Posted by Graves

I'm about to crack 10k miles and wanna put a BM3 Stage 1 on it. I have dogged this car out. 170+mph sustained runs on the autobahn, zero issues. Not sure if I should worry about it or leave it stock.

High speed runs don't spin the hub. It is low end torque.

So doing 170 mph pulls doesn't affect it

[Graves]

Originally Posted by deeldoo

High speed runs don't spin the hub. It is low end torque.

So doing 170 mph pulls doesn't affect it

1 - 3 shifts? Once you in speed I would assume the violence of shifts would be less painful on the motor.

[Bmwlmr99]

glad I'm not doing whatever it is you guys are doing to crash your engine....90,000 miles, full bolt on intake, dp , exhaust...csf intercooler...stage 2....Nooooooo issues

[Graves]

Originally Posted by Bmwlmr99

glad I'm not doing whatever it is you guys are doing to crash your engine....90,000 miles, full bolt on intake, dp , exhaust...csf intercooler...stage 2....Nooooooo issues

Most of it probably boils down to driving habits. Glad to see you haven't had any issues.

[Vegetable]

I have 84,000 miles on my '19 M4 with BM3 stage 1 since 5,000 miles.. no issues. In fact this has been the most reliable car I have ever owned, except for my Toyota Corolla that somehow made it to 270,000 miles with only needing its digital clock replaced.

[White340]

Originally Posted by Vegetable

I have 84,000 miles on my '19 M4 with BM3 stage 1 since 5,000 miles.. no issues. In fact this has been the most reliable car I have ever owned, except for my Toyota Corolla that somehow made it to 270,000 miles with only needing its digital clock replaced.

That's where they get ya! Engine will last forever but digital clock replacement costs a grand 😛

[Djdnav]

Originally Posted by danchee

Those that I have been able to find are either tuned or stock at higher mileage than the 2300 miles. Can you point me to the other threads where stock cars are getting spun crank hubs at that low miles?

There was one a while back with a guy that it happened when backing out of the driveway.. I believe 5-7k and stock. There’s no proven correlation between model year/power level/mileage; regardless of what some randoms declare as truth.

[damageprone]

Originally Posted by Vegetable

I have 84,000 miles on my '19 M4

[deeldoo]

Originally Posted by Djdnav

There was one a while back with a guy that it happened when backing out of the driveway.. I believe 5-7k and stock. There's no proven correlation between model year/power level/mileage; regardless of what some randoms declare as truth.

Power matters but not what typically people think

I have taken a long look at this hub and the impression from a mechanical perspective is that the only thing that can cause loosening or slipping of that bolt is the dct transmission shifting hard into gear.

The thudding you feel in between hard S3 shifts do transmit a fair bit into the crankhub assembly.

Granted it isn't 1 shift that causes it to back out, overtime the vibrations and impact add up. Thats why you hear the case of the guy driving out of his driveway and that first shift pops it loose.

Where the power comes in is that E85 cars just take a very quick time to do it and are frequently driven by track rats who use the agressive shifting, launching, etc.

Eventually if the bolt hasn't been torqued right even a stock or slightly tuned car would eventually spin if you are driving in S3.

This car would have 0 issues driving around in S1 or S2 with no kickdowns.

It's the power transmitted between shifts that causes the back out.

The solution is toss a CBC on and let the car thud all it wants between shifts.

I think BMW tried to mitigate some of this garbage situation with the bedplate design revamped but it didn't do enough. Now we are at the end of it's life cycle so we move on.

[Bmwlmr99]

I drive in s3 mod all the time , no issues...do roll races 30,40,60 miles per hr , downshift etc.... no hub mods

[Graves]

Originally Posted by deeldoo

Power matters but not what typically people think

I have taken a long look at this hub and the impression from a mechanical perspective is that the only thing that can cause loosening or slipping of that bolt is the dct transmission shifting hard into gear.

The thudding you feel in between hard S3 shifts do transmit a fair bit into the crankhub assembly.

Granted it isn't 1 shift that causes it to back out, overtime the vibrations and impact add up. Thats why you hear the case of the guy driving out of his driveway and that first shift pops it loose.

Where the power comes in is that E85 cars just take a very quick time to do it and are frequently driven by track rats who use the agressive shifting, launching, etc.

Eventually if the bolt hasn't been torqued right even a stock or slightly tuned car would eventually spin if you are driving in S3.

This car would have 0 issues driving around in S1 or S2 with no kickdowns.

It's the power transmitted between shifts that causes the back out.

The solution is toss a CBC on and let the car thud all it wants between shifts.

I think BMW tried to mitigate some of this garbage situation with the bedplate design revamped but it didn't do enough. Now we are at the end of it's life cycle so we move on.

I would assume in this case then that a CBC would be all you ever need to keep the bolt from backing out. So, why ever do the full crank hub fix?

[deeldoo]

Originally Posted by Graves

I would assume in this case then that a CBC would be all you ever need to keep the bolt from backing out. So, why ever do the full crank hub fix?

The reason it should ever be done is because if your bolt has stretched or backed out already then having the capture still allows the friction disc to spin the hub.

If the bolt is right tight with the friction disc in there bound in the cbc installed won't allow anything to spin as it is cemented in tight.

From what i looked at is the bolt starts slowly loosening reducing the frictional coefficient even if you were to put the cbc you still risk the friction disc going as it has already started backing out.

So in short it requires the bolt to come loose in some sort of shape/form to be able to spin the friction disc.
As you can see in another post someones 2 pin hub went to hell because the bolt backed out.

I don't think there is any way to guarantee your bolt hasn't already stretched or backed out though but i do think the few that it occurs on are already not torqued properly from factory and if they spun they would have already went.

This is why in europe alot of shops do cbc only but with this comes a torquing from their shop so they know everything is tight before capturing it. Also i think there is a way to check from datalogging if your timing is slightly off but not enough to throw a CEL