Pictured - 5 M3 / M4 S55 engine vehicles in our workshop for crank hub upgrades
Many of you are already very familiar with the spun crank hub (SCH) issue on the S55 engine that comes in the M3 / M4 / M2C. If you happen to be one of the few that isn’t as familiar then fear not, you’re about to learn everything you need to know and more. We won’t be going too in depth on the SCH issue itself (since this forum is already so saturated with this information), but rather we will be focusing on the concept of the keyed crank hub fix and the installation of it.
Although the SCH issue seems to be so prevalent and openly talked about on the forum, it seems there are some questions or gaps to fill in for many when it comes to the process behind implementing / installing a keyed crank hub fix kit on the S55 engine. We went out of our way to create this write up / video demonstration in hopes of changing that!
We hope that this write up / video can help you visualize and understand the concept of the BMW S55 engine keyed crank hub upgrade as well as familiarize you with the core steps and procedures necessary to install it.
Let’s Begin!
WHAT IS A “KEYED CRANK HUB UPGRADE” AND WHY DO I NEED IT?
The keyed crank hub upgrade is a replacement of your stock crank hub unit with a unit that has four “keys” or “pins” for which 4 holes are drilled into the S55 crankshaft so that upon installation of the crankshaft bolt the new keyed crank hub can be locked into place permanently without a chance of relative rotation to the crankshaft. This allows further insurance against the chance of the crank hub “slipping” or “spinning” and un-syncing the relative angles between the crankshaft and camshafts (this can mean engine failure which will cost upwards of $20,000 to replace or at the very least leave you stranded and un-driveable until the crank hub is replaced and engine is retimed). This SCH failure has been seen on both modified and stock S55 engines. If you are modifying your car, tracking your car, or even driving spiritedly, then upgrading your crank hub is highly recommended.
IS MY CAR ON THE LIST OF AFFECTED VEHICLES?
2015+ BMW F8X M3 / M4 (CS / GTS)
2019+ BMW F87 M2C
And any other variation of BMW models utilizing the S55 engine
WHAT WILL BE NEEDED TO REPLACE MY STOCK CRANK HUB?
Two-Piece Keyed Crank Hub Kit (Maximum PSI design style crank hub used in this example)
(
https://www.ssrperformance.com/produ...740027e7&_ss=r)
OEM Gaskets & Parts Needed
∙ Valve Cover Gasket Set
∙ Front Crank Seal - Crankshaft Seal
∙ Bolt for Timing Chain Sprocket - Intake/Exhaust Camshaft
∙ Cover Seal for Brake Booster Vacuum Pump
∙ Oil Pan Gasket
∙ Engine Oil Pan Bolt Kit (Aluminum)
∙ Coolant / Antifreeze (Blue) (1 Gallon)
∙ Engine Oil - 5W-30 Synthetic (7 Liters)
∙ Oil Filter Kit
Labor
∙ Valve Cover R&R (8.2 hours BMW book time)
∙ Oil Pan R&R (8.4 hours BMW book time)
∙ Front Crank Seal R&R (5.6 hours BMW book time)
∙ Drilling Crankshaft (1.5 hours approximated)
∙ Crank Hub R&R w/ proper torquing procedure and retiming engine (1.5 hours approximated)
Total Approximate Labor Hours: 25.2 Hours (BMW specialty tools required)
MAXIMUM PSI CRANK HUB DISCONTINUED?
As already mentioned by a few individuals on this forum, Maximum PSI has discontinued the sales of their two piece keyed crank hub. The main reason for Maximum PSI discontinuing the crank hub was increased production costs and overseas companies copying the design and undercutting Maximum PSI's prices. It got to the point where Mike, owner of Maximum PSI, decided that profit to effort ratio was no longer valuable enough for them to continue offering the product (just one of the many the difficult decisions business owners are expected to make).
However, a two piece crank hub can still be purchased on SSR Performance's website. Here is why...
Due to the fact that I have had a close business relationship with Mike over at Maximum PSI since years ago, Mike was kind enough to pass over the information so that we can continue to offer this solution direct from the manufacturing facility that Maximum PSI was working with to produce these.
Mike's unselfish act has allowed for this solution to still be offered to the end consumer through outlets like us.
With full consent from the owners of Maximum PSI we still offer a two piece crank hub now with 4 pins on our website and it will continue to be available for purchase ONLY while supplies last or until any further notice is given.
UPGRADED 4 PIN DESIGN?
Welcome the new and improved 4 pin design! As can be seen in the photo above, as well as on our website (
click here to go to the product page), the latest revision of the crank hub has been upgraded to 4 pins as opposed to the previous design which had 2. The new design is meant only to further decrease the chance of failure and not by any means was it changed due to any failures.
As it stands there is still a 100% success rate of the previous 2 piece 2 pin crank hub since we took over on the distribution of them, however that doesn't mean there wasn't room for improvement. The engineering / machining facility that is in charge of the manufacturing of this product was given the opportunity to improve on the previous design and did so based on their extensive knowledge of materials science and machining.
As mentioned above, based on the physical characteristics of this system, this new 4 pin design will only further guarantee the integrity of the product and ultimately offer our customers an even greater peace of mind!
DISCLAIMER:
This write up / video is for educational / entertainment purposes only. This video is not meant to be a tutorial or instructions on how to replace your S55 engine’s crank hub. This procedure requires specialty tools and S55 engine specific knowledge and therefore should only be performed by a facility that specializes in BMW engines.
Now let's move onto the fun stuff
enjoy
CLICK PLAY HERE TO WATCH THE FULL INSTALLATION PROCESS HAPPEN IN ACTION
OR
CONTINUE SCROLLING TO SEE THE WRITE UP
FULL WRITE UP
2019 BMW M2 Competition (S55 Engine)
Thanks for watching!
Contact Info: Please feel free to contact us for any questions that you may have!
Website: www.SSR-Performance.com
Email: info@SSR-Performance.com
Phone: (800) 438-2808
Instagram: @SSRperformance (follow us to stay updated!)
590 W Freedom Ave Orange, CA 92865 (open by appointment)