Bilstein 25-176223 B8 5165 Remote Reservoir 46mm Monotube Off-Road Suspension Shock Absorber

The Bilstein B8 5165 (MPN: 25-176223) is a high-performance remote reservoir monotube shock absorber engineered for custom off-road builds, lifted light trucks, and SUVs. Built around Bilstein's proven 46mm monotube gas pressure technology, this shock delivers consistent, fade-free damping even under the most punishing off-road conditions.

The external remote reservoir dramatically increases oil capacity for superior heat dissipation, while a floating dividing piston relocates the gas charge out of the shock body — maximizing usable piston travel and extending wheel articulation beyond what a traditional shock absorber can offer. Patented digressive valving instantly responds to changing terrain, providing full damping control without sacrificing bump compliance.

Key Features:

• 46mm monotube construction — consistent, fade-free performance in all conditions
• Remote reservoir — increases oil capacity for greater heat dissipation and extended wheel travel
• Floating dividing piston located in the reservoir for maximum shaft travel
• 360° swivel banjo hose fitting — allows clean, low-profile reservoir hose routing
• 5/8-inch eye-to-eye mounting with hourglass bushings on both ends
• Collapsed length: 13.64 in. | Extended length: 22.4 in.
• Digressive valving — self-adjusts to surface changes for maximum vehicle control
• Zinc coating with multi-layer Bilstein finish for corrosion and off-road element resistance
• Made in the USA
• Reservoir mounting hardware and detailed instructions included
• Optional billet aluminum reservoir clamp available separately

The B8 5165 series is sold individually and is available in multiple collapsed lengths and valve rates to suit a wide range of custom suspension setups. A 90-day limited warranty against defects in materials and workmanship is included.