[waldrops]

So I'm one of the wildly paranoid "please don't void my warranty" kind of guys. I've only got 2k miles on the car and already am drooling at the thought of going catless DP and flash tune.

My dilemma lies with the dreaded S55 crank hub disaster. If I install a Maximum PSI Keyed Crankhub, do I really have much else to worry about on the tuned S55 platform? I understand that statistically my chances of being one of the few are low, but I don't want to have to worry.

https://maximumpsi.com/products/maxi...it-s55-n55-n54

PS: Not worried about minor tuned car related upgrades (intake, chargepipe, etc...)

[brad65ford]

Welcome to what everyone else is worried about to it seems. There are a good bit of thread already about it, platform and many many of these motors have been created for years now so there is enough data to support some type of percentages etc.. Plan to do key if I go bigger turbo, that's how I'm looking at it for now.

[BroDoze]

While I'm thrilled this option exists, I still cannot believe these things are necessary on a $60K car to "fix" it. Absurd.

With labor, this is like another $4K-$5K on top of the entry price.

Shame on you BMW.

[msdss]

fwiw, the keyed fix has already been proven to fail.

[Thescout13]

Originally Posted by BroDoze

While I'm thrilled this option exists, I still cannot believe these things are necessary on a $60K car to "fix" it. Absurd.

With labor, this is like another $4K-$5K on top of the entry price.

Shame on you BMW.

Well I guess then shame on every other car manufacturer ever. Think BMW is the only manufacturer with less than 0.1% stock engine failure rates?

I assume you don't work in any type of manufacturing business and understand FFRs and Epidemic Failure numbers.

[brad65ford]

Talk to these guys, seems they may have a solution

[Proctor750]

M4 GTS has the same crank hub as you and has 500hp from the factory. Your just as likely to fail at those levels as you are now.

It's Russian roulette bub (but with a revolver with tens of thousands of empty chambers).

[1mm2]

Originally Posted by Proctor750

It's Russian roulette bub (but with a revolver with tens of thousands of empty chambers).

This.

It seems to happen with no rhyme or reason.

[F87source]

I've also heard it could be attributed to how the S55 has 2 HPFP's driven on the cam which causes more stress on the crank on downshifts which leads to slippage. It could also be because the S55 has alot more things that are mechanically driven such as the water pump, which can cause more stress on that little friction disk (which is there to prevent the crank from spinning instead of a keyed hub) and this increases the stress on the crank letting it slip easier.

But honestly it seems to be really random tbh, plus it only seems exacerbated to us forum guys because along with the few frequent forum members, everyone with the issue (and have never even been on a forum) seems to run online to post about it which ends up on the forum for discussion. If you look at it this way there are alot of S55's out there but such a small percentage have failed, and when you take into account modded m4's that percentage only increases slightly.

So imo I wouldn't stress about it too much.

[F87source]

Originally Posted by BroDoze

While I'm thrilled this option exists, I still cannot believe these things are necessary on a $60K car to "fix" it. Absurd.

With labor, this is like another $4K-$5K on top of the entry price.

Shame on you BMW.

VTT has a solution called the "SPLOCK" and it doesn't require the motor to be pulled, disassembled, and the crank to be machined. So labour (for those that can't DIY it or don't have the tools to do so) should be more tolerable at the $1k range.

But I've also heard the slippage of the crank is primarily caused by the crank bolt backing out so VTT's crank hub capture unit should also be another supporting mod to lower those failure rates even further.

[waldrops]

Originally Posted by F87source

VTT has a solution called the "SPLOCK" and it doesn't require the motor to be pulled, disassembled, and the crank to be machined. So labour (for those that can't DIY it or don't have the tools to do so) should be more tolerable at the $1k range.

But I've also heard the slippage of the crank is primarily caused by the crank bolt backing out so VTT's crank hub capture unit should also be another supporting mod to lower those failure rates even further.

Yeah, VTT's two part system is also the only aftermarket fix with no reported failures.

[F87source]

Originally Posted by waldrops

Yeah, VTT's two part system is also the only aftermarket fix with no reported failures.

Yeah the splock idea is great, but I also have heard that some cranks are actually "soft" and the splock will shear it but again I have no idea if this is true.

But honestly it is probably the most worth it solution so far since the motor doesn't have to be torn apart, and if you do have to tear apart the engine it's probably cheaper to buy a used one.

[tom @ eas]

We cover the VTT Splinelock in this thread, applies to M2C also:

▀▄ eas | VTT "SplineLock" CrankHub Installation Overview for S55
https://f80.bimmerpost.com/forums/sh....php?t=1561598

[FreeDarko]

Originally Posted by waldrops

Yeah, VTT's two part system is also the only aftermarket fix with no reported failures.

Which other solutions have we seen here that has failed?

[Dav3]

Originally Posted by waldrops

So I'm one of the wildly paranoid "please don't void my warranty" kind of guys. I've only got 2k miles on the car and already am drooling at the thought of going catless DP and flash tune.

My dilemma lies with the dreaded S55 crank hub disaster. If I install a Maximum PSI Keyed Crankhub, do I really have much else to worry about on the tuned S55 platform? I understand that statistically my chances of being one of the few are low, but I don't want to have to worry.

https://maximumpsi.com/products/maxi...it-s55-n55-n54

PS: Not worried about minor tuned car related upgrades (intake, chargepipe, etc...)

My dilemma revolves around the long-term reviews of the current crank hub fixes

Based on what I've read about aftermarket fixes for similar issues on other BMW's, some of the aftermarket stuff ended up doing more damage than good

Unfortunately a lot of people downplay warranty because the odds favor you but imagine absorbing 15,000$ of engine replacement cost. Even worse if you're tied through a lease or a long term rental contract.

Unfortunately also, tuning the M2C on paper is really worth it. 100+ real hp gain for 500$ is an absolute steal. Especially if you're coming from the N55 where you'd need to spend 10,000$ to get anywhere close.

[BroDoze]

In USD, you’re looking at like $25K for an S55 replacement.

[doughboy]

Originally Posted by BroDoze

In USD, you’re looking at like $25K for an S55 replacement.

Yes, but - if my engine "blew", even big style threw a rod or something and i had no warranty i'd not buy a full new engine at retail from BMW!

I'd buy a ex M3 or M4 (or M2C if lucky) S55 short motor from a breakers and get the engine rebuilts from that (not by BMW either).

BMW would push a new engine for even minor internal damage because their technicians don't repair / rebuild engines, they just fit new ones.

You'd need to go outside to a proper engine shop and just get it repaired.

[waldrops]

Originally Posted by FreeDarko

Which other solutions have we seen here that has failed?

Gintani, maximum psi, and essentially all the Keyed solutions have had rare failures. When a keyed one fails it destroys the engine, leaving no option but a new engine.


The spine lock has had reported failures, but only in situations where the owner only installed the CBC(crank bolt capture) or the Spline lock hub, not both. Per VTT, they both serve different purposes, and when placed in conjunction with one another no failures have been reported thus far.


I did a pretty extensive forum search and couldn't fine one either.

[doughboy]

It seems that various hub designs have failed but no one has had a slip with a cbc fitted?

I've had the Litchfield cbc fitted, makes more sense to me than trying to change the hub design.

The bolt won't back out, more like the cbc secures the hub to the bolt...

[waldrops]

Originally Posted by doughboy

It seems that various hub designs have failed but no one has had a slip with a cbc fitted?

I've had the Litchfield cbc fitted, makes more sense to me than trying to change the hub design.

The bolt won't back out, more like the cbc secures the hub to the bolt...

yes, I read about one with only a cbc and it has failed.

[F87source]

The cheaper alternative like mentioned above is buying a short block from a wrecked car and utilizing that. Or going for a rebuild with forged internals if your block isn't completely damaged.

Overall the car's cam position sensor is good enough to catch the slip and limp mode the engine before damage occurs in most cases.

But this is why I'm afraid of the S55 with the crank hub failure, oil cooler failure, and intercooler leaks which can all cause some serious damage. So far it seems like the M cures lives on.

[hellrotm]

This car has plenty of power stock. Enjoy the car and warranty, just drive.