EVERYTHING You Need To Know About The S55 Crank Hub - BMW M2 M3 M4

[@RSXengineering]

To be 100% correct, crankhub failure on the S55 is due to aggressive variations of engine speed, not power or torque. This is more frequent with tuned DCTs which commonly have faster downshift and kickdown speed. This is also possible on manual cars *just like you mentionned* by a missed shift or other driver error.

[@Al-vl3tp]

I brought the precision designer Motorsports one piece CrankHub that will be completed by GDO in Central Jersey. I was going to go with Auto Coutore as well but I'm getting other FBO on my car as well. I have the same car. 2018 M Comp 6MT with 81k miles all stock but I'm getting it done next week!

[@lMSOELITE]

Time for some power! You will most definitely fall in love with the car all over again when you finish the tuning process E85 is night and day difference Can’t wait to see sound clip video with downpipes. We have the same mods (I still have stock muffler though)

[@RicardoDavidson]

Another great video, appreciate all the information, I’ll be going down this road eventually for my peace of mind.

[@Autofreakgarage]

Good choice! Any questions along the way, let me know!

[@leobats14]

Wow lots of information. Fantastic video sir. Well played.

[@seezang]

Great info, im in the process of getting my done soon

[@Autofreakgarage]

Let me know if you have any questions!

[@speedtribex]

As an ex BMW Specialist Mechanic here in Malaysia, I can say that if you had 100 cars to check data most probably none of them would spin the crankhub. But also as an ex BMW Specialist Mechanic I will say knowing the quality that BMW make these parts that part is not up to the quality standards for some reason. My advice would be this, 1. If you know a good workshop that knows what they're doing & 2. If you can afford the premium prices of said workshops, get it done. If you can't afford it or don't 100% trust the workshop, don't do it. It's better to leave it be, because an improper installation which happens more often than you think is A LOT worse than leaving it stock. 😀 Just leaving my 2 cents here because I have a lot of experience with these cars and unless you drive of mod your cars like a lunatic it will be fine, I've worked on cars that have over 100k miles and are still running strong even after it's been to the track a lot.

[@10SecChacko]

Question. I’m sure you’ve seen or herd of crank hubs done improperly, so when workshops or DIYers do the crank hub what are mistakes you’ve seen?

[@speedtribex]

@@10SecChacko The most common problem that could happen is also the most 'fatal', it would be the drilling of crank shaft, ie the holes for the new crank hub pins. Even they're off by a bit you can feel it when installing the new crankhub. You shouldn't need more a slight push for new hub to enter the drilled holes in the shaft. If it's not done correctly it will lead to the crankhub spinning, in which case it would have been better leaving it stock. The pins on the new hub will snap and it'll happen quite quickly after the installation, a lot of times the force of just turning onn the car will make the crankhub spin if it wasn't done properly. Another thing to look out for, which is not exactly a mistake, it's the tools to lock the timing in place when doing the crankhub. It requires special tools, if a workshop doesn't have the tool and they say they can do it, RUN. My ex boss now friend has 2 sets of all sizes of the tools for different engines, he's been working on BMW's longer than I've been alive, 20+ years. It can be done without the special tool but it's harder, easier to fck up, and also takes a lot more time. SO if they don't have the tool it means the don't do such extensive jobs often, which means they definitely don't know how to a crankhub. This tool is also why I would highly not advice this job to done at home, the special tool is quite expensive. 😁 If you can afford it at a good shop get it done, if you can't or don't want to spend the money. Don't us the kickdown feature, tbh you should be fine, unless you running E85 or just super duper unlucky. Stage 2 bootmod is fine too, just no kickdown or E85.

[@RB26DETT_]

@@speedtribex Hi, I appreciate your thorough response to the above question and I had another question I was hoping you could help with - would you say the MMR crank hub is a good idea in terms of preventative maintenance? It doesn’t require any drilling so I’m questioning the integrity of it, given it’s not drilled into the crankshaft. For your reference, I have a M2 competition with around 30,000kms on it and completely stock. I’m planning on changing the exhaust and intake (for sound mostly) and then flashing it with the OEM M2 CS tune (roughly 30kw more power) as I think it’s ‘safe’ due to the M2 CS sharing all engine components that I have in my M2 Competition but coming with more power from the factory. All your thoughts and feedback are welcome. Thanks

[@FidermanX]

Wow! You dodged a big one. Awesome work.

[@ashishpatel350]

love the way bmw's look and drive. hate the way they build them to fail catastrophically.

[@pw85___]

You ain't lying!

[@Autofreakgarage]

With any performance oriented motor with such high tolerances, it’s just the name of the game. But thankfully, we have the aftermarket community to solve them. Out of all the M3’s prior, this is a fairly easy solution to bulletproof the motor.

[@theDRIPg0d]

​@@AutofreakgarageI disagree. Bmw makes their parts in plastic and crank hub issues should not be a failure norm. But bmw owners just accept all the car failures like it's not a big deal. It is a very big deal. Bmw cars and motorcycles are very flawed.

[@Autofreakgarage]

And what about the Shelby gt350 voodoo motor oiler filter backing off from vibrations? What about the focus rs faulty head gaskets? What about the 991.1 Porsche gt3 motors where the connecting rod bolts loosening and causing fires? It doesn’t matter what performance oriented motor or brand it may be. High strung, high tolerance sport car motors pushing the limits will have certain limits. It’s the name of the game. And plastics? Check every single car that is on the streets today uses plastics. Even Porsche, Lamborghini, Ferrari… they all have plastic components.

[@moee585]

thanks for this info. I also heard that it’s more than likely for the crank hub to go bad with adding 550 go and more (correct me if I’m wrong). Also, what’s your thoughts regarding the stock charge pipes, I heard they can potentially crack from all the temperature change? (Which we get a lot of in the tri state)

[@Autofreakgarage]

I was completely stock on power and as you can see, my friction discs were cracked. I’d do this whether you are stock or modified. Change the charge pipes as well. Known to crack over time and when adding more power.

[@ralphpeiris5996]

I can’t believe your friction washer broke. How in the hell did that happen? The crank hub is not a cheap fix. I have 2017 BMW M3 competition with DCT. I baby the car and it is on the back of my mind to fix it.

[@Autofreakgarage]

I was just as surprised as you. Glad I did it!