Bilstein 25-284584 Suspension Shock Absorber - Rear Left

Bilstein B8 8100 (Bypass) Shock Absorber Overview

The Bilstein B8 8100 (Bypass) shock absorber, part number 25-284584, is engineered for Lexus and Toyota SUVs including the 4Runner, GX460, and GX470. Designed to enhance suspension performance, this shock absorber offers precise control through adjustable damping for both compression and rebound.

• Double adjustable damping – compression and rebound
• Bypass body design (non-coilover) with 60mm diameter
• Monotube internal design for consistent performance
• Includes remote reservoir for improved heat dissipation
• Zinc plated finish for corrosion resistance
• Collapsed length: 14.72 inches (374 mm), extended length: 24.09 inches (612 mm)
• Lower mount type: Eye 19.3mm; Upper mount type: Stem

About the B8 8100 (Bypass) Product Line

The B8 8100 (Bypass) series by Bilstein is designed to provide advanced suspension tuning through its bypass body design. Unlike coilover shocks, this non-coilover monotube shock absorber features an external reservoir that allows for better heat management and consistent damping performance. The double adjustable damping system enables fine-tuning of both compression and rebound settings, making it suitable for drivers seeking customizable suspension behavior on Lexus 4Runner, GX460, and GX470 models.

Detailed Product Description

This Bilstein shock absorber utilizes a monotube internal design paired with a bypass body to deliver reliable and adjustable suspension control. The 60mm body diameter and zinc plated finish contribute to durability and corrosion resistance. With a collapsed length of 14.72 inches and an extended length of 24.09 inches, it fits the specified Lexus and Toyota SUVs precisely. The inclusion of a remote reservoir improves heat dissipation during demanding driving conditions, maintaining consistent damping performance. The double adjustable damping feature allows users to independently adjust compression and rebound, tailoring the ride quality and handling characteristics to their preferences.

Common Applications and Problem Solving

• Improves handling and stability on Lexus 4Runner, GX460, and GX470 models
• Reduces body roll and enhances cornering control
• Addresses suspension fade caused by heat buildup during off-road or heavy-duty use
• Restores ride comfort by allowing fine-tuning of compression and rebound
• Replaces worn or damaged OEM shocks for consistent performance

Installation Notes and Tips

Ensure compatibility with Lexus 4Runner, GX460, and GX470 models before installation. The shock absorber features an eye lower mount (19.3mm) and a stem upper mount, so verify mounting points for proper fitment. Adjust damping settings after installation to match driving conditions and personal preferences. Professional installation is recommended to ensure correct torque specifications and alignment.

Quality Assurance and Warranty

Bilstein shock absorbers are manufactured to meet strict quality standards, featuring durable materials and corrosion-resistant finishes. The monotube design and remote reservoir contribute to long-lasting performance. For warranty details, refer to Bilstein’s official documentation or contact the manufacturer directly.