By now, you’ve either owned a 4x4 or have been in one that has a set of Bilstein 5100 shocks on it. They’ve been a great stock replacement shock for a number of years, and now Bilstein has decided to improve upon its own product and offer a remote reservoir version of the same stock-replacement shock in some different lengths and valving for today’s all-purpose off-road vehicles.
The 5160 shock uses a completely remote reservoir that has an internal floating piston (IFP) inside it with shock oil on one side and nitrogen on the other. By having the separating piston inside the reservoir instead of at the top of the shock (body), the 5160 shock can offer one or two more inches of travel than a 5100 shock on the same vehicular application.
Though the 5160 is a direct-fit, application-specific shock, Bilstein also offers a 5165 remote reservoir shock in various valving configurations with 6 to 14 inches of stroke.
The Bilstein 5160 shocks come standard with rubber isolators and hose clamps to mount the reservoir, but we opted for Bilstein’s billet clamp (part # 11-176015). The 5160s are rebuildable, but they need to be converted with either a kit or by sending them back to Bilstein for the rebuild.
Out of the box, the shocks are charged to 200 psi, which is less than a standard monotube shock, but the reservoir function makes the shock require less pressure to function just as well. The benefit to a lower shock pressure is less spring rate in the shock—that translates into a smoother ride.