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Off Road Shock Absorbers 101 - Shocking News

Probably The Most Overlooked And Most Important Part Of Your Suspension

By Cole Quinnell, Photography by Cole Quinell, Courtesy of the Manufacturer
Some new vehicles come with coilover suspension, which allows companies like Bilstein and Rancho to provide better shocks and a lift, all in one package. The Rancho QuickLift shown for the 2006-and-later GM 1500 reuses the factory coil spring, but others are available with new springs. Both Bilstein and Rancho make systems for these vehicles that lift the vehicle as much as 2 3/4 inches. In some applications, this makes room for 35-inch tall tires.
Some new vehicles come with coilover suspension, which allows companies like Bilstein and

The first change to shock design for 4x4s has been larger shock bodies. This is a relatively inexpensive way to increase oil volume. Shock lengths for lifted vehicles are generally longer, but the diameter of the shock body may also be increased in some applications, depending on the space available under the rig. The second way to increase oil volume is by employing a remote reservoir. This solution was developed for off-road racing, and has become popular for all types of 4x4s. A remote resevoir allows you to use a smaller shock-body diameter, while increasing oil volume by putting it in a separate reservoir connected by a hose or tube. There is also some additional heat dissipation realized through a greater combined surface area of the shock and remote reservoir.

Another type of shock that you'll see on modified 4x4s is a coilover shock. This combines the shock and spring of a suspension system into one assembly. These are popular in a custom setup because you can combine components within the same space. Coilover assemblies also allow taller springs than a traditional coil-spring suspension because the springs are completely captured. You can change springs easily to alter the spring rate, or "frequency", as suspension engineers prefer to talk about. You can also create a dual, or triple-rate springs by putting two or more springs with different frequencies on one coilover assembly. This can give you a soft ride for the first few inches of compression, and a more aggressive spring frequency for situations when suspension travel moves beyond the normal range.

A coilover shock combines the spring and shock in one unit for excellent packaging. They generally deliver very long travel because the coil springs are captured. The Rancho Pro Series RS9000LX (shown) incorporates two springs divided by a mid-mount (A). Each coil spring has a different frequency for a dual-rate performance. Most coilovers also feature variable ride height that is easy to adjust with a threaded lower spring mount (B). This Rancho coilover also includes the company's nine-position adjustability feature and a remote reservoir.
A coilover shock combines the spring and shock in one unit for excellent packaging. They g

Almost all current light-duty pickup trucks come with coilover shocks from the factory, including the new Dodge 1500, GM 1500s, Ford F-150, as well as all Nissan and Toyota vehicles. This has created an opportunity for traditional shock companies to offer a combination of a improved dampers and a lift in one component.

Shock valving is typically engineered specifically for each application. For example, a high-quality shock absorber to fit a GM truck that's lifted six inches has been valved to accommodate the larger tires and handling characteristics of that lifted vehicle. Additionally, some shocks have user-adjustable valving, allowing you to soften the shocks when desired, such as during rockcrawling, and tighten them for towing or generally highway driving.

It's not too surprising, but you generally get what you pay for. If you simply drive back and forth to work, a low-dollar shock will suffice, though additional performance gains can be attained from a higher-quality shock-a must for serious trail work.

The Rancho MyRide wireless remote control system uses air pressure to adjust the RS9000XL shocks. This saves you from having to reach under your rig and adjust the shocks individually, and you can program your settings in the memory of the unit. The small air compressor provides pressure to the receiver, which gets signals from the remote and sends air pressure as needed to the shocks. The kit comes with everything you'll need for installation.
The Rancho MyRide wireless remote control system uses air pressure to adjust the RS9000XL

Shock Swap: One of the Easiest Mods to Do Yourself
Unlike changing gears in your axles or installing a complete IFS lift kit, changing shocks is an easy job to do yourself. And the improvement in ride and performance can be very gratifying. To show you just how easy it is, we installed a set of Rancho RS9000XL shocks on a 2008 Wrangler. This installation is typical of most non-coilover applications.

The RS9000XL shocks feature nine valving levels that you can set and adjust whenever you want. Adjustments are made by turning a knob at the base of each shock. You can also tune the shocks differently front-to-rear. We like a moderate setting for highway and a super-soft setting for rockcrawling. We took our install one step further by adding the Rancho MyRide system. This is a wireless remote control system for the adjustable RS9000XL shocks. With the system, we can program our specific front and rear settings for highway, rockcrawling and other driving conditions, and then choose each singular setting with the push of a button. Then we can put the controller in the console or glovebox when we're done. No need for permanently mounted switches or gauges.

Generally, installing shocks takes less than one hour per shock. Our installation took most of a day because we added the MyRide system.

  • Because we were installing the MyRide system, the first step was to remove the manual adjustment knobs from all four shocks. The MyRide kit even includes the Allen wrench you'll need to do this. If there is any gasket material left on the shock body, remove it. We decided to keep one of the manual knobs in our glovebox in case trail damage claimed one of the new air-line fittings. The fittings bolt on with new gaskets, reusing the Allen bolts.
    Because we were installing the MyRide system, the first step was to remove the manual adju
  • To install the front shocks, we raised the vehicle and secured it on jack stands so we could remove the front tires. On the rear, we didn't need to remove the tires. With the vehicle raised, unbolt and remove the old shocks. Stack one rounded washer and polyurethane bushing on the threaded portion of the piston rod. Insert the top part of the rod in the shock mount and install the second bushing, rounded washer and nut. The Rancho shock has a nut welded to the rod below the mount, so you can use a wrench to keep the rod from spinning as you tighten the upper nut.
    To install the front shocks, we raised the vehicle and secured it on jack stands so we cou
  • The shock is gas pressurized, so you will need to compress it to get it in the lower mount. We used a long screwdriver to move it within the mount to align shock and mount. Re-use your existing lower shock-mount bolt. Don't overtighten the bolt, as this can bend the mount tabs. The rear shocks use a T-bar with two bolts on the upper mount, but are otherwise the same to install. In three hours, we had all four shocks swapped.
    The shock is gas pressurized, so you will need to compress it to get it in the lower mount
  • Mount the compressor underhood, near the battery. In our application, there was enough space between the battery and the airbox. The compressor only runs when you are actually adjusting the shock settings, so there's little risk of it overheating from use, making mounting locations a bit easier than other types of air compressors. We mounted the receiver on the outside of the battery isolation box (arrow).
    Mount the compressor underhood, near the battery. In our application, there was enough spa
  • Route the black air line along the chassis, making sure that it won't come in contact with hot or sharp objects. Use lots of zip-ties to securely fasten the air line. At the shock, make sure you leave enough slack to accommodate suspension travel. You may want to attach it to the brake lines. The connection at the receiver and the shocks is extremely easy: Make sure the cut on the hose is clean, and push the air line into the socket.
    Route the black air line along the chassis, making sure that it won't come in contact with
  • With the system completely installed, you can program the specific settings you like in the controller or use default settings. We played with a bunch of settings, front and rear, to find exactly what worked well for us. And we love how easy it is to select the desired setting once it's programmed.
    With the system completely installed, you can program the specific settings you like in th
SOURCES
Rancho Suspension
1 International Drive
Monroe
MI  48161
734-384-7804
www.gorancho.com
Pro Comp Suspensions, Inc.
2360 Boswell Road
Chula Vista
CA  91914
619-216-1444
www.explorerprocomp.com
Walker Evans Racing
P.O. Box 2469
Riverside
CA  92516
888-933-7223
www.walkerevansracing.com
Bilstein
14102 Stowe Drive
Poway
CA  92064
858-386-5900
http://www.bilsteinus.com
By Cole Quinnell
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