A Permanent Fix for the Factory Crank Hub Problem
The factory crank hub used in BMW’s N55 and S55 engines is a well-known weak point, particularly as power levels increase. The OEM design uses three individual sprocketed pieces that drive the timing chains off the crankshaft. Importantly, none of these sprockets are mechanically linked together nor to the crankshaft . They rely only on friction washers and the clamping force of the crank bolt to stay aligned.
Under higher horsepower, rapid throttle transitions, hard launches, or even completely stock operation, the friction surfaces can slip. When this happens, the timing components rotate out of alignment, causing the engine to fall out of mechanical timing. This can quickly lead to bent valves, piston-to-valve contact, or catastrophic engine failure.
A True Mechanical Solution Instead of More Friction:
The 034Motorsport 1-Piece Pinned Crank Hub replaces the entire multi-piece factory stack with a single CNC-machined billet EN36 steel unit. By combining all timing sprockets into one rigid body, every driven timing component remains physically linked, eliminating the possibility of internal hub slip.
You can configure the hub in the way that best suits your build:
Unpinned Installation
The 034 design can be installed in an unpinned configuration using the factory crankshaft with no drilling required. This setup works seamlessly with the included Crank Bolt Capture Plate, which locks the crank bolt in position and prevents any chance of bolt movement.
Pinned Installation (Recommended for Heavy Abuse/High Power)
For those who want maximum mechanical security, the hub can also be installed in a 4-pin configuration, physically interlocking it with the crankshaft. One of the key advantages of the 034Motorsport Crank Hub is that it eliminates the need for a separate hub version. You can choose pinned or unpinned using the same part.
To ensure safe and accurate drilling, the kit includes a carbide drill bit and a dedicated drill guide and alignment jig. Most competing kits only provide a high-strength steel drill bit, which wears quickly when cutting into the crankshaft.
Crank Bolt Capture Plate: The Second Layer of Defense
Machined from 6061-T6 billet aluminum and anodized for long-lasting protection, the Capture Plate surrounds and locks the OE crank bolt in place, preventing any possibility of bolt walk-out. Paired with the 1-Piece Hub, this configuration eliminates both crank bolt and crank hub slip, protecting against the most common N55/S55 timing failures.
Elongated mounting slots allow the Capture Plate to be used with both OE and 034Motorsport crank hubs, ensuring a precise and secure installation.
Built to Protect Your Engine, No Matter the Power Level:
From aggressively tuned street builds to fully track-prepped cars, the 034Motorsport 1-Piece Pinned Crank Hub and Capture Plate system is engineered to be the definitive solution for securing the crank hub. With uncompromising materials, precision engineering, and a complete installation package, this upgrade delivers the reliability and confidence your BMW deserves.
Upgrade once. Protect forever.
1-Piece Crank Hub Features:
- 1-Piece CNC-Machined Hub, Installable In 4-Pin Or Unpinned Configuration
- Prevents Crank Hub Slip And Failure On High-Power Engines
- Billet EN36 Steel, Heat-Treated With 0.75 Mm Case Hardening
- High-Strength Design Built For Extreme Power And Abuse
- Optional Precision Dowels Mechanically Lock Hub To Crank (Crank Drilling Required)
- Complete Installation Kit: Jig, Guide, Locating Bolt, And Carbide Drill Bit
- Includes New OE Crank Bolt
Crank Bolt Capture Plate Features:
- Machined From 6061-T6 Billet Aluminum
- Anodized For Durability And Long-Lasting Finish
- Surrounds And Locks OE Crank Bolt, Preventing Loosening
- Fits 034Motorsport Or OE Crank Hub With Elongated Slots For Secure Install
- Prevents 3-Piece Crank Hub Slip On S55 And N55 Engines
- Installs With Engine In-Situ By Dropping Radiator For Access
