KYB SM5858 Suspension Shock Mounting Kit - Rear Upper

KYB Rear Upper Strut Mount SM5858

KYB SM5858 is a rear upper suspension shock absorber mounting kit built for OE-style replacement on select Scion and Toyota applications. It addresses worn vibration insulators and bearing components that can add noise, harshness, and steering looseness.

Key Features

• OE-quality replacement strut mount for application-specific fitment
• Superior rubber helps reduce noise, vibration, and harshness
• Mount bearings promote smoother steering response and help maintain front-end alignment
• Front bearing plates support vehicle weight and act as steering pivots where equipped
• Matched-grade studs and nuts for proper component matching

Product Details

As part of KYB Mount Components, the SM5858 is engineered to restore suspension isolation and steering feel in the rear upper mount position. KYB focuses on replacement components that follow original equipment design intent, helping return the suspension to proper operation after the original mount has hardened, cracked, or worn. This part number, SM5858, is a direct-fit solution for drivers searching for a rear upper strut mount for 2012-2015 Scion iQ, 2008-2014 Scion xD, 2012-2014 Toyota Prius C, and 2007-2014 Toyota Yaris.

This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

What It Helps Address

• Clunking or rattling from worn rear upper mount components
• Excess cabin noise from hardened vibration insulators
• Harshness transmitted through the suspension over bumps
• Loose or imprecise steering feel caused by worn bearing components
• Front-end alignment concerns related to mount wear where applicable

Installation Notes

Install SM5858 in the rear upper position only on the listed vehicles. Inspect the surrounding strut assembly, spring seat, and related wear items before installation, and verify that the replacement mount matches the original configuration for the application. Professional installation and alignment checks are recommended after suspension service.

Quality Assurance

KYB is known for OE-style suspension replacement parts, and the Mount Components line is built to restore factory-like ride control and steering response. SM5858 is designed around application-specific requirements for the listed Scion and Toyota models, including Scion iQ, Scion xD, Toyota Prius C, and Toyota Yaris.