4-Piece Front Lower Forward Control Arm and Ball Joint Set

Precision Suspension Restoration for BMW X3 and X4 Models

Restore the legendary "Ultimate Driving Machine" road feel to your BMW with this comprehensive 4-Piece Front Lower Forward Control Arm and Ball Joint Kit. These components, often referred to as "thrust arms" or "tension struts," are the primary defenders against braking vibration and steering instability. Over time, the heavy-duty hydraulic bushings in these arms tend to leak or crack, leading to sloppy steering response, front-end "shudder" under braking, and uneven tire wear.

This kit provides a total refresh for the forward section of your front suspension. By replacing both the aluminum control arms and the specialized lower forward ball joints simultaneously, you ensure that the entire geometry of the front axle is returned to factory specifications. Each part is precision-engineered from high-grade aluminum and steel to match the weight and performance characteristics of the original BMW chassis.

Fitment Verification and Vehicle Applications

This 4-piece kit is designed for the Front Lower Forward position on the following BMW Sport Activity Vehicles:

• BMW X3 (F25 Chassis): 2011, 2012, 2013, 2014, 2015, 2016, 2017.

• BMW X4 (F26 Chassis): 2015, 2016, 2017, 2018.

• Compatibility: Fits all sDrive and xDrive variants (28i, 28d, 35i, M40i).

• Fitment Note: These are the forward-facing arms in the dual-lower control arm suspension setup.

Technical Specifications and Attributes

• Quantity: 4-Piece Set (Complete Left and Right Forward assemblies).

• Material: Lightweight, High-Strength Aluminum Alloy.

• Bushing Type: Pre-installed Premium Hydraulic/Rubber Bushings.

• Ball Joints: (2) Heavy-Duty, Maintenance-Free Forward Ball Joints.

• Finish: Natural Aluminum for superior corrosion resistance.

• Fitment Type: Direct Replacement.

What’s in the Box

• (2) Front Lower Forward Control Arms (LH & RH)

• (2) Front Lower Forward Ball Joints (LH & RH)

• Note: High-strength mounting nuts for the ball joint studs are typically included.

Industry Cross-Reference Numbers

• BMW: 31106787665, 31106787673, 31106787674

• MOOG Chassis Products: K500312

• Dorman - OE Solutions: 522-889, 522-890

• Delphi: TC3232, TC3233

• Mevotech Supreme: CMS101252, CMS101253, MS10566

• Beck/Arnley: 102-7795, 102-7796

Installation and Technical Tips

• Torque at Ride Height: This is the most critical step for BMW suspension longevity. Do not perform the final tightening of the bushing-to-chassis bolts while the vehicle is suspended on a jack or lift. Lower the vehicle onto its wheels (or onto drive-on ramps) so the suspension is under its own weight before applying final torque. Tightening at full "droop" will pre-load the rubber, causing the new bushings to tear prematurely.

• Professional Alignment Required: Replacing the thrust arms will alter your vehicle's toe and caster settings. A professional 4-wheel alignment is mandatory immediately after installation to ensure straight tracking and to prevent rapid tire wear.

• Specialized Ball Joint Tooling: Removing the original forward ball joints from the steering knuckle often requires a specialized ball joint separator. Using a "pickle fork" is not recommended as it can damage the steering knuckle or surrounding components.

• Hardware Replacement: BMW often utilizes "torque-to-yield" fasteners (one-time use stretch bolts) for suspension mounting. It is highly recommended to source new Grade 10.9 or higher mounting bolts for the chassis side to ensure safety and proper clamping force.