KYB SB118 Suspension Strut Bellows - Front or Rear

KYB Strut Boot Kit for OE-Style Protection

KYB Boot Kits help protect the strut shaft from dirt, dust, sand, salt, and other road debris that can wear on seals and bushings. The SB118 also includes a poly foam travel-limiting bumper to help prevent bottoming out and reduce damage from extreme suspension movement.

Compatible With select BMW X3 and X4 front applications, plus Mazda CX-5, Protege, MX-3, and 323 rear applications, this KYB strut boot kit is built for direct-fit service where the original bellows has worn or failed. The KYB Boot Kits line focuses on durable protection for the exposed strut shaft and surrounding components.

Key Features

• Superior-quality boot helps protect the strut shaft from leak-causing dirt and debris
• Poly foam bumper helps prevent the strut from bottoming out
• Protects the upper seal and bushing from contamination
• Built to match or exceed OE design and quality
• Designed specifically for Mazda applications

Detailed Description

The KYB SB118 suspension strut bellows covers the strut shaft with a durable plastic boot to help keep abrasive contaminants away from critical wear surfaces. By shielding the polished shaft, upper seal, and bushing, it supports longer service life for the strut assembly. The integrated foam bumper adds travel control during compression, helping reduce harsh contact when the suspension reaches its limit. This part cross-references Monroe Shocks & Struts (e.g., 63620) for the same application.

Fits 2015-2018 BMW X4, front. Fits 2011-2017 BMW X3, front. Fits 2013-2016 Mazda CX-5, front. Fits 1990-1998 Mazda Protege, rear. Fits 1992-1995 Mazda MX-3, rear. Fits 1986-1994 Mazda 323, rear, excluding electrically adjustable suspension.

What It Helps Address

• Damaged or torn strut bellows
• Contamination on the strut shaft from road debris
• Wear at the upper seal caused by dirt and salt exposure
• Harsh suspension contact from bottoming out
• Premature strut wear from exposed components

Installation Notes and Tips

Inspect the strut shaft, seal, and bushing before installation. Replace the boot when the original bellows is cracked, split, or missing, and verify vehicle position and suspension type before ordering. For Mazda 323 applications, confirm the vehicle is not equipped with electrically adjustable suspension.

Quality Assurance

KYB is known for OE-focused suspension engineering, and the SB118 is built to the same design and quality standards expected from a direct replacement boot kit. The part number is SB118.