Which Direction Should Rancho® Shocks Be Installed?
Getting It Right
Installing shocks in the correct direction is crucial to a successful repair. Learn how to determine ‘which end is up’ to correctly install Rancho® shocks.
Does Shock Orientation Matter?
How do you know which way a Rancho shock is supposed to be installed? It’s easy - most Rancho shocks are designed to be install rod UP and body DOWN. This includes the Rancho RS5000®X and RS9000®XL shocks which both feature a light gas charge. These shocks aren’t designed to work upside down. Twin-tube (RS5000X) and triple-tube (RS9000XL) shocks feature an additional compression valve that is located at the bottom of the damper hydraulically coupling the tubes. When the damper is installed rod down, this moves the shock valve to the top of the damper and the shock oil can’t flow through it as designed since all the oil will settle down near the rod. Mounting the shock rod UP and body DOWN correctly positions the compression valve at the base of the damper where the internal oil reservoir is. In addition, it protects the shock rod from nicks that can occur from debris on the road or trail.
The exception to this rule is Rancho RS7MT® shocks. Monotube shocks (RS7MT) inherently do not have the second compression valve as there is only one tube. In this instance, the high pressure gas charge is separated by the shock oil by a dividing piston. The orientation does not matter due to the valving always being submerged in oil. While these dampers can be mounted rod down, RS7MT shocks are designed by Rancho engineers to be mounted rod up to protect the rod from damage.
Inside the Issue
The confusion often happens when replacing a loop-style rear shock on a half-ton, ¾-ton or 1-ton truck. The OEM shock on the truck MAY have the shock positioned with the rod down and you might assume that the Rancho shock is installed the same way. However installing the Rancho shock like the OEM shock results in poor ride performance. All the oil is now at the bottom of the TOP of the shock body, NOT working on the shock rod end where the valve shim stack is, so the shock isn’t working. Once shock is flipped, it will work. Be sure to install the shock rod up.
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