Blackline Limited Slip Differential - BMW Axle 168 - E21 - E30 - E36 - X3 E83 - X5 E53 - Z3

The Blackline limited slip differential for BMW E21, E30, E36, X5 E53, X3 E83, and Z3 models with differential 168—also known as an LSD (limited slip differential)—improves traction by distributing torque between the two-wheel drive drive wheels based on available grip.

Its helical gear design allows the limited slip differential to transmit more torque to the wheel with the best traction. As torque increases, the gears exert pressure against the differential housing and generate the internal friction necessary for this torque distribution. The system can thus handle a significant difference in drive force between the two wheels, particularly during heavy acceleration out of a turn or when traction is limited.

Under light loads, the helical limited slip differential maintains smooth, progressive, and quiet operation. The wheels can continue to rotate at different speeds when necessary, particularly when cornering. This feature improves traction during spirited driving while maintaining handling suitable for on-road use.

The Blackline limited slip differential uses a parallel-shaft helical gear architecture optimized to distribute forces. Its 5:1 torque split means that when one wheel loses traction, the wheel with the most traction can receive up to five times the torque transmitted to the spinning wheel.

As with any helical-gear limited slip differential, a minimum amount of resistance must remain on the wheel with the least grip to allow torque transfer. It is therefore most effective when both wheels maintain a minimum level of resistance. This technology also works particularly well in conjunction with modern ABS systems.

The Blackline HLF021 limited slip differential is designed for several BMW models equipped with a 168 differential. Specific applications vary depending on the model, engine type, and differential position. It installs as a direct replacement for the original differential on compatible models. Its housing and gears are made of high-strength 8620 steel.

Technical Specifications of the Blackline limited slip differential for BMW E21, E30, E36, X5 E53, X3 E83, and Z3

Manufacturer Part Number: HLF021
Quaife Application Equivalent: QDF6N
Type: Helical-gear limited slip differential
Compatibility with BMW E21:
- BMW E21 315
- BMW E21 316
- BMW E21 318
- BMW E21 320i
- BMW E21 323i without factory limited slip differential
BMW E30 Compatibility:
- BMW E30 318i
- BMW E30 318is
Compatibility with BMW E36:
- BMW E36 316i
- BMW E36 318ti
- BMW E36 318is
- BMW E36 320i
BMW X5 E53 Compatibility:
- BMW X5 E53 4.4i automatic - front differential
- BMW X5 E53 4.6is - front differential
Compatibility with BMW X3 E83:
- BMW X3 E83 3.0d - front differential
- BMW X3 E83 3.0sd - front differential
Compatibility with BMW Z3:
- BMW Z3 1.9 - mechanical transmission
- BMW Z3 2.0 - mechanical transmission
Differential type: BMW 168
Torque split ratio: 5:1
Housing and gear material: High-resistance 8620 steel
Mounting: Direct replacement for the original differential on compatible models

Key features of the Blackline limited slip differential for BMW with 168 differential

• Torque split between the wheels based on available traction.
• Transmits more torque to the wheel with the best traction.
• Immediate and progressive reaction to changes in traction.
• Smooth, progressive, and quiet operation.
• No friction discs for reduced maintenance requirements.
• Power delivery that is easily controllable, especially during spirited driving and drifting.
• Housing and gears made of high-resistance 8620 steel.
• Direct mounting for the original differential.