Ultimate Spun Crank Hub (SCH) Poll: ALL Members Please Vote!

[IK6SPEED]

Originally Posted by Smeargle

If you get a hub changed(just the hub) which is more often than not the case for warranty claims, the hub is prone to going again shortly after because retiming the motor is a very hard job and most dealers can't do it. So yes.

Hmmmm

So out of 238 (technically) votes, count is actually 28.

9 2014-2015
3 2016
3 2017
13 2018

Years label corrected.

[Tall Tom Cruise]

Originally Posted by IK6SPEED

Hmmmm

So out of 238 (technically) votes, count is actually 28.

9 2014-2015
3 2015
3 2016
13 2018

*owns a 2018 DCT and uses kickdown in S3 often*

[FriedPiston]

Originally Posted by IK6SPEED

Hmmmm

So out of 238 (technically) votes, count is actually 28.

9 2014-2015
3 2015
3 2016
13 2018

You may have missed one from an MY2017

2017 | DCT | Modified 550+ whp | SCH Failure = 1

Seeing the reports for MY2018 is a bit scary. It makes you wonder if BMW rushed the 2018s out to push sales.

[Bmwlmr99]

Originally Posted by Tall Tom Cruise

*owns a 2018 DCT and uses kickdown in S3 often*

hahahahaha.....Damnit man...56k stage 2 tune no issues....calm down

[Tall Tom Cruise]

Originally Posted by Bmwlmr99

hahahahaha.....Damnit man...56k stage 2 tune no issues....calm down

Lol. Is yours a 2018? And how many miles out of the 56K have you been stage 2? Seems like the running theory is that for 2018 models they may have incorrectly torqued X amount from the factory.

I'm planning on going BM3 within the next few weeks.

[Bmwlmr99]

Originally Posted by Tall Tom Cruise

Lol. Is yours a 2018? And how many miles out of the 56K have you been stage 2? Seems like the running theory is that for 2018 models they may have incorrectly torqued X amount from the factory.

I'm planning on going BM3 within the next few weeks.

originally had a piggyback at 20k, upgraded to stage one at 27k , stage 2 at 46k....however I've never ran E85 or methanol injection....just 93 octane, no drifting or hard launches at the drag strip every weekend

[IK6SPEED]

Originally Posted by nars3000

You may have missed one from an MY2017

2017 | DCT | Modified 550+ whp | SCH Failure = 1

Seeing the reports for MY2018 is a bit scary. It makes you wonder if BMW rushed the 2018s out to push sales.

I labeled 2015/2016 incorrectly.

My mistake.

Will correct.

Also...grasping at straws...drivetrain change in Nov 2017 (MY 2018).

Would be interesting to know which drivetrains the 2018 failures have been.

michaelf80 msmching projectme numairk moonshine89 MDriver2000 aspahn Ziggy66 2SNAILS ey2001 F806speed Smeargle

[FriedPiston]

Originally Posted by IK6SPEED

Also...grasping at straws...drivetrain change in Nov 2017 (MY 2018).

Would be interesting to know which drivetrains the 2018 failures have been.

Interesting for sure. What was the drivetrain change for MY2018 in Nov 2017?

[IK6SPEED]

Originally Posted by nars3000

Interesting for sure. What was the drivetrain change for MY2018 in Nov 2017?

https://f80.bimmerpost.com/forums/sh....php?t=1411862

Given the GRADUALLY REPLACED line, I am not sure November 2017 is a clear date that can be be universally used.

[FriedPiston]

Originally Posted by IK6SPEED

https://f80.bimmerpost.com/forums/sh....php?t=1411862

Given the GRADUALLY line, I am not sure November is a clear date that can be be universally used.

Ahh, IIRC, this change didn't take effect until after March 2018.

[IK6SPEED]

Originally Posted by nars3000

Ahh, IIRC, this change didn't take effect until after March 2018.

Just read through thread. That appears correct.

As I said, grasping for straws.

[Smeargle]

Originally Posted by IK6SPEED

I labeled 2015/2016 incorrectly.

My mistake.

Will correct.

Also...grasping at straws...drivetrain change in Nov 2017 (MY 2018).

Would be interesting to know which drivetrains the 2018 failures have been.

michaelf80 msmching projectme numairk moonshine89 MDriver2000 aspahn Ziggy66 2SNAILS ey2001 F806speed Smeargle

6spd

[projectme]

Mine was a mis click, never had the issue

[alphakinase]

I made an account to answer the survey. Currently own a 2015 M4 DCT with no SCH problems.

But it's worth mentioning that a survey such as this has really low power to determine the actual percentage of failures in a given model year run.

As an example, if there were 2000 M4 DCTs in the 2014 - 2015 run (actual production may be a bit higher) and we managed to survey 100 people about their SCH problems, at a 95% confidence interval that gives a margin of error of 10%....

Let's say we get 100 responses (quite optimistic) for that run and get a failure rate of 5%. At a margin of error of 10%, all we can say is that the rate of SCH failure is less than or equal to 15%. Quite an absurd number - if 15% of those vehicles were failing, there likely would have been a recall or service bulletin in my opinion.

We may get enough responses to generate some statistical power by summing responses across all model years and WHP levels, but because the mods and years may themselves affect the rate of SCH failure, it's hard to say with any confidence what such data means in the real world.

In other words, only BMW will ever know the real rate of SCH failure.

That said, I'm all for this survey and hope as many people as possible fill it out!

[2SNAILS]

Originally Posted by projectme

Mine was a mis click, never had the issue

+1
So was mine!
Car runs perfect

[IK6SPEED]

Originally Posted by alphakinase

I made an account to answer the survey. Currently own a 2015 M4 DCT with no SCH problems.

But it's worth mentioning that a survey such as this has really low power to determine the actual percentage of failures in a given model year run.

As an example, if there were 2000 M4 DCTs in the 2014 - 2015 run (actual production may be a bit higher) and we managed to survey 100 people about their SCH problems, at a 95% confidence interval that gives a margin of error of 10%....

Let's say we get 100 responses (quite optimistic) for that run and get a failure rate of 5%. At a margin of error of 10%, all we can say is that the rate of SCH failure is less than or equal to 15%. Quite an absurd number - if 15% of those vehicles were failing, there likely would have been a recall or service bulletin in my opinion.

We may get enough responses to generate some statistical power by summing responses across all model years and WHP levels, but because the mods and years may themselves affect the rate of SCH failure, it's hard to say with any confidence what such data means in the real world.

In other words, only BMW will ever know the real rate of SCH failure.

That said, I'm all for this survey and hope as many people as possible fill it out!

It’s not a random survey of BMW S55 owners so no matter the n= count, it will not be scientific.

You cannot accurately predict margin of error [B]to the real world[B] in a non-random sample survey. You can only predict margin of error to the universe of owners that opted in on Bimmerpost.

[alphakinase]

Originally Posted by IK6SPEED

It’s not a random survey of BMW S55 owners so no matter the n= count, it will not be scientific.

You cannot accurately predict margin of error [B]to the real world[B] in a non-random sample survey. You can only predict margin of error to the universe of owners that opted in on Bimmerpost.

Might be right - I'm not a statistician, just an enthusiast.

Either way I think we can agree that the survey is of little value in determining the true rate of failure - which is exactly the information someone making the choice of keeping/selling or buying into the M3/4 world would want to know in order to make their decision.

So these results should be looked at with a high degree of skepticism. Still they're likely to be of interest to the community here, especially if there is an obvious trend towards a certain model year, setup, or WHP number. We'll need a good number of responses to get at that information though.

[numairk]

Originally Posted by 2SNAILS

+1
So was mine!
Car runs perfect

Mine was also a mis click on mobile

[TheONE24]

I'm on mobile and can't seem to vote.

[IK6SPEED]

Originally Posted by numairk

Mine was also a mis click on mobile

Originally Posted by TheONE24

I'm on mobile and can't seem to vote.

Android or Apple?

[Bigsean714]

Just voted, hopefully we can keep this thread going! Really interesting.. barley any people seem to be having the crank hub issue, it's really making me want to flash stage 1 lol.

[Pic18]

Originally Posted by alphakinase

In other words, only BMW will ever know the real rate of SCH failure.

You are assuming that every single person who has had a failure has brought the car to a BMW dealer, although the overall numbers are pretty low, I am sure that some of the cars out of warranty may have been brought straight to a specialty shop and not BMW direct.