SuperPro SPF4328K Rear Subframe Mount Bushing Set for Select BMW 1999-2021 (3-Series / M3 / Z4)

Fits select 1999-2021 BMW 323i, 323Ci, 325i, 325Ci, 328Ci, 330i, 330Ci, M3, and Z4 (sDrive28i / sDrive30i / sDrive35i / sDrive35is / 2.5i / 3.0i / 3.0si).

Subframe bushings are critical connection points between the suspension and the chassis. Manufacturers typically use soft, heavily-voided rubber bushings to maximize isolation, but as this rubber ages, it allows excessive movement. This degradation negatively impacts traction, handling precision, and can cause significant wheel hop under acceleration or gear changes. The SuperPro SPF4328K kit replaces these worn components to restore and enhance performance while maintaining a high level of isolation.

Engineered from high-grade synthetic elastomer, these bushings provide a more stable mounting platform for the rear subframe. Unlike traditional rubber, this material is resistant to environmental contaminants and does not lose its physical properties over time under heavy load cycles. This upgrade is essential for high-performance driving or for restoring the precise handling characteristics of older chassis.

• Part Number: SPF4328K
• Location: Rear Subframe Mount
• Material: Proprietary Synthetic Elastomer
• Reduces wheel hop and drivetrain movement
• Improves suspension geometry stability and throttle response
• Resistant to oils, fuels, and UV exposure