KYB SM5257 Shock Mount - Rear Upper

KYB SM5257 Rear Upper Strut Mount

Restore suspension isolation and steering feel with the KYB SM5257 rear upper strut mount. This KYB Mount Components part is built as an OE-quality replacement for select BMW applications, helping reduce the vibration, noise, and harshness that worn mounts can transmit into the cabin.

Compatible With 1998-2006 BMW rear upper suspension applications, including BMW 325Ci, 330Ci, 325i, 325xi, 330i, 330xi, Z4, M3, Z3, 323Ci, 323i, 328Ci, and 328i, depending on model and suspension package.

Key Features

• OE-quality replacement strut mount for precise suspension service
• Superior rubber construction helps reduce noise, vibration, and harshness
• Mount bearing design supports smoother steering response and alignment retention
• Matched-grade studs and nuts for application-specific fitment
• Engineered to replace hardened vibration insulators that degrade ride quality

Product Details

The KYB SM5257 is part of KYB’s Mount Components line, focused on restoring the function of suspension mounting points with application-specific replacement parts. On rear upper BMW suspension locations, a worn mount can create clunks, excess cabin vibration, and inconsistent ride behavior. This mount helps isolate road impacts while maintaining the support needed for stable suspension operation. This part cross-references Monroe Shocks & Struts 904966 for the same application.

Common Problems This Part Addresses

• Rear suspension noise over bumps or rough pavement
• Excess vibration transferred into the vehicle body
• Harsh ride feel caused by deteriorated mount rubber
• Reduced steering smoothness from worn bearing surfaces
• Alignment instability related to worn front-end or suspension support components

Installation Notes and Tips

Verify the vehicle’s suspension package before ordering, since some BMW models listed exclude M-Technik, Sport, or Adaptive Control Suspension configurations. Confirm the rear upper mounting location and compare the original mount to the KYB SM5257 before installation. Inspect surrounding suspension components, fasteners, and bearing surfaces for wear so the new mount is installed into a serviceable assembly.

Quality Assurance

KYB is known for OE-style suspension replacement components, and this mount is built to meet the fit and function expectations of the original application. The KYB SM5257 is designed to restore proper mount performance on select BMW rear upper suspension setups while maintaining the quality standards associated with KYB Mount Components.