BTKUSA X3/X4 M/M40I Adjustable Rear Lower Control Arms

BTKUSA X3M/X4M & X3/X4 M40i Adjustable Rear Lower Control Arms

MADE IN USA 🇺🇸

FITMENT NOTICE: These Rear Lower Control Arms are designed to fit BOTH the BMW X3M/X4M and X3/X4 M40i platforms. The same control arms are compatible with both models.

BTKUSA BMW Adjustable Rear Lower Control Arms (RLCA)

The BTKUSA Adjustable Rear Lower Control Arms were engineered to improve rear suspension rigidity, increase alignment adjustability, and provide greater control over suspension geometry for the BMW X3M/X4M and X3/X4 M40i platforms.

Lowering these vehicles changes the factory suspension geometry, which can affect rear wheel alignment, tire wear, and overall handling characteristics. Our adjustable RLCA design provides the ability to fine-tune rear suspension alignment, allowing for a more precise setup for street, drag, track, or aggressively lowered applications.

Each arm is CNC machined from billet aluminum, providing an extremely rigid yet lightweight construction. Starting with approximately 20 LBS of aluminum, the arms are precision machined down to just 7.4 LBS for the complete pair, removing unnecessary material while maintaining structural strength where it matters most.

The adjustable design allows for greater control over rear suspension alignment compared to the factory arms. This is especially beneficial for lowered vehicles where factory adjustment may not provide the range needed to achieve the desired suspension setup.

With the X3M/X4M and X3/X4 M40i being heavier, higher center-of-gravity platforms, maintaining proper rear suspension geometry and rigidity is especially important for predictable handling, stability, and consistent suspension performance.

Designed with both form and function in mind, the BTKUSA Rear Lower Control Arms combine precision machining, increased adjustability, and an exceptionally rigid construction to provide a comprehensive upgrade over the factory components.

From the initial design and material sourcing to the final machining and finishing process, every step is proudly completed in the USA.

Features

• CNC machined billet aluminum control arms
• stainless steel sleeves for better load distribution and longevity 
• Adjustable rear suspension alignment
• Increased alignment adjustment range compared to factory
• Increased rigidity compared to factory control arms
• Lightweight construction — just 7.4 LBS per pair
• Precision machined to minimize unnecessary weight
• Designed for lowered street and track applications
• Improved ability to fine-tune rear suspension geometry
• Premium anodized finish
• Designed and manufactured in the USA 🇺🇸
• Sold as a complete pair
• type 2 hard anodized 

Applications

BMW X3M / X4M

• BMW F97 X3M
• BMW F97 X3M Competition
• BMW F98 X4M
• BMW F98 X4M Competition

BMW X3 / X4 M40i

• BMW G01 X3 M40i
• BMW G02 X4 M40i

Sold as a complete pair.

Made in USA 🇺🇸