SPC 721204 Repl Ball Joint for SPC 72123/72125 Upper Control Arms 03-08 350Z/G35

Vehicle Fitment

• 2003-2008 Nissan 350Z (All Trims, RWD, VQ35DE / VQ35HR 3.5L V6) - when equipped with SPC 72123 or 72125 front upper control arms
• 2003-2007 Infiniti G35 Coupe (All Trims, RWD, VQ35DE 3.5L V6) - when equipped with SPC 72123 or 72125 front upper control arms
• 2003-2006 Infiniti G35 Sedan (All Trims, RWD, VQ35DE 3.5L V6) - when equipped with SPC 72123 or 72125 front upper control arms

Fitment Notes

• CRITICAL: This ball joint is NOT a vehicle-direct-fit part - it is exclusively a replacement for the ball joint housed within SPC's 72123 and 72125 front upper adjustable control arms
• Also compatible with Eibach 5.72123K front upper control arms, as those arms are manufactured by SPC Performance
• Does NOT fit OEM factory control arms or any other aftermarket control arms other than SPC 72123 / 72125 (and the Eibach-branded equivalent)
• Sold individually; one ball joint required per side - two required for a full front axle replacement
• Fitment is for RWD (rear-wheel drive) variants only; the Infiniti G35 AWD sedan used a different front suspension configuration
• SPC arm 72123 supersedes the earlier 72125; both arm generations use this same 721204 replacement ball joint

Features

• Sliding and rotating ball joint design allows simultaneous camber and caster fine-tuning within the SPC 72123/72125 arm's full adjustment range (-1.5° to +3.5° camber, ±1.0° caster)
• Greasable construction for extended service life - allows periodic lubrication to maintain smooth movement and prevent premature wear
• Dust boots included to protect the ball joint from contamination, moisture, and road debris
• OEM-equivalent strength - designed to restore the original performance and structural integrity of the SPC adjustable arm without replacing the entire arm assembly
• Direct drop-in replacement into the SPC arm housing - no modification required to the arm, knuckle, or surrounding hardware
• Cost-effective service solution - replaces only the worn ball joint rather than requiring full control arm replacement
• Manufactured in the USA by SPC Performance, the industry leader in adjustable alignment components since 1971
• Aircraft-quality materials used throughout for high strength, fatigue resistance, and long-term durability under performance and daily-driving conditions

Specifications

• Part Number: 721204
• Compatible SPC Arms: 72123, 72125 (and Eibach 5.72123K)
• Position: Front Upper (Left or Right)
• Ball Joint Type: Sliding and Rotating (Camber + Caster Adjustable)
• Camber Adjustment Range (within arm): -1.5° to +3.5°
• Caster Adjustment Range (within arm): ±1.0°
• Greasable: Yes
• Dust Boots Included: Yes
• Drivetrain Compatibility: RWD
• Quantity: Sold individually (1 per side)
• UPC: 082642721291

Included Components

• 1x SPC 721204 Replacement Ball Joint Assembly
• 1x Dust boot

Product Description

The SPC Performance 721204 is a replacement ball joint assembly designed exclusively for use with SPC's 72123 and 72125 front upper adjustable control arms on the 2003-2008 Nissan 350Z and 2003-2007 Infiniti G35 Coupe and 2003-2006 G35 Sedan (RWD). Over time, the sliding and rotating ball joint inside the SPC arm can wear - particularly on vehicles that see track use or frequent alignment adjustments - producing looseness, noise, and diminished alignment precision. The 721204 allows the ball joint to be replaced independently, restoring the arm to full operating condition without the expense of replacing the entire control arm assembly.

This is a vehicle-indirect fitment part: it is not a factory ball joint replacement and will not fit OEM control arms or any other aftermarket arms. It is specifically engineered to seat into the SPC 72123 and 72125 arm housings, and is also compatible with the Eibach 5.72123K front upper arms, which are produced by SPC. Once installed, the ball joint restores the arm's full adjustment capability - up to -1.5° to +3.5° camber change and ±1.0° caster change - enabling precise alignment dialing for lowered, track-prepared, or alignment-corrected 350Z and G35 builds.

Built with the same aircraft-quality materials and manufacturing standards as SPC's complete arm assemblies, the 721204 ball joint is greasable for extended service life and includes a dust boot to protect the joint from contamination. It is sold individually; one unit is required per side for a full front axle service. This replacement ball joint is the recommended service solution when an SPC 72123 or 72125 arm remains in good structural condition but the ball joint itself has worn beyond specification - a common maintenance item for high-mileage or track-used examples.