Lang Racing S55 Keyed Crank Hub Kit M3 M4 M2C

Our S55 crank hub kit is a reboot of the original Maximum PSI crank hub fix kit with a couple small improvements. Metallurgy and heat treat process has been improved from the original kit. Like our other product lines this kit is produced entirely in the US with no compromises on quality. We use aircraft quality US made steel. We use a double heat treat process to extend life. We also superfinish the surface to decrease chain wear. We worked closely with the chain manufacturer to optimize the design of this product rather than simply copying the dimensions from BMW. Large volume local production has allowed us to reduce the price a bit and bring savings to our shop partners and customers. Please check the bulk pricing discounts on this page for more information.

The S55 even in stock form can suffer from crank hub failure. The single bolt design uses friction washers to hold engine timing and just isn't a robust design, particularly for increased boost or racing applications. This design keys the crank hub to the oil pump drive chain, timing chain drive, and crankshaft. The multi piece design also makes installation easier. Other designs on the market are more cost effective to produce because they are single piece units. Unfortunately this makes installation more difficult. While you may save money on the product using these other designs, your installer will likely charge more to install it. This kit comes with an improved drill bushing to ensure that your installer can confidently drill holes into the crankshaft straight. We provide comprehensive installation support on this product via phone and email.

Kit Includes:

• Carbide Drill Bit Required for Drilling Hardened Crankshaft
• 2 Piece Hub Design
• Drill Fixture
• Drill Fixture Bolt
• OEM Crank Bolt

Applications:

• BMW F80 M3 (2015 - 2018)
• BMW F82 M4 (2015 - 2018)
• BMW F82 M2 Competition (2019)