SPC Performance 81388 Audi A4 Racing Control Arms

These arms directly replace the factory fixed-length upper links, unlocking front camber and caster adjustability that the OEM suspension simply does not provide — an essential upgrade for lowered vehicles or track-focused builds where precise alignment is critical.

The kit delivers ±1.5° of camber and ±1.5° of caster adjustment on both sides of the front axle. The standout feature is the proprietary xAxis™ sealed flex joint, which replaces the overly compliant OE rubber inner bushings with a free-pivoting, minimum-compliance joint. Unlike a traditional heim joint, the xAxis™ joint is fully sealed to retain grease and exclude contaminants, making it suitable for both street driving and track use. The result is dramatically reduced suspension deflection, sharper steering response, and more consistent alignment under load.

Key Features:

• Forged 6061-T6 aluminum construction — maximized strength at minimum weight
• xAxis™ sealed flex joints with highly polished electroless-nickel finish and up to 45° of angularity for high misalignment requirements
• OE-style, maintenance-free booted ball joints for long service life
• Large 18mm threaded adjuster links for precise, repeatable adjustment
• Replacement pinch bolts included
• Adjustment range: Camber ±1.5° / Caster ±1.5°
• Estimated installation time: 0.7 hours per side
• One kit covers the complete front axle (both sides)

⚠ NVH Warning: The OE rubber bushings are engineered to absorb noise, vibration, and harshness (NVH). By replacing them with xAxis™ flex joints, this kit will transmit increased road noise and vibration into the cabin. This is an expected and accepted trade-off for the performance gains delivered. Drivers seeking full OEM NVH levels should consider SPC part #81383 (OE-type bushing version).

For single-side applications, the left-side kit is available as #81381 and the right-side kit as #81382. Replacement ball joint boot kits are available under part #81354.