Looking to upgrade your truck’s shock absorbers (also known as dampers) to improve its off-road performance? Sometimes it’s hard to know where to start, especially when not all the information out there is good information. To help us bust some myths and steer the correct course to off-road suspension performance, we spoke with Bryan Grigsby, former off-road racer and now director of Holley’s Off-Road and UTV Business Unit.
“Always select the correct damper for your application and use case,” advises Grigsby. “Not all shocks are the same. For example, I see lifted trucks with dual external-bypass shocks that are no help at all in that street application. A quality monotube damper should provide better ride quality for a lifted truck, but it too may not be the best shock for your application if you are using the truck for off-road excursions as well as for towing or hauling heavy loads in your everyday work.
“In this case, you might want to consider a tunable shock with sufficient volume, such as the 2.5-inch Mesa monotube made by ADS, or a reservoir shock that has an adjuster,” he continues. “If one day you’re riding around with the bed empty, and the next day you’re hauling 1,000 pounds of lumber or other heavy cargo, you can simply make an adjustment with the dial and the vehicle will maintain its ride quality.”
Meanwhile an overland user requires something suitable for long-range, low-speed recreational wheeling. Here too, it’s important that the valving and spring rate are properly matched to maintain the correct damping and control for the weight of the truck, even though the solution will be different.
“The shock temperatures will be lower, so you likely won’t need a separate reservoir,” Grigsby explains. “Again, the Mesa is a good, direct-fit option. It’s different for ‘prelanding’ however, where you’re loaded up and traveling at high speed across the desert or through the forest. You’ll need to bump up the damping capability by going up to a larger shock body-size and consider bypass shocks for the rear axle, too.”
Shop ADS Racing Shocks Mesa 2.5 Series performance shocks here.
Grigsby adds that the correct shock specification for a particular use is a combination of the damper diameter, length, reservoir, fluid lines, fittings, and even shock oil – all matched, of course, to the correct spring rate to maintain ride performance.
Static spacers are an inexpensive way to add ride height to a truck to accommodate a larger wheel-and-tire package. But, Grigsby warns, a spacer is not the optimal way to achieve that lift because it overstresses the factory components.
“Adding a spacer essentially adds spring preload, and thus changes the effective rate of the spring,” he explains. “You’ve also moved the shock piston out of the location that it was designed to ride in by the OEM. That could lead, for example, to a lot less available piston travel in the droop (rebound) zone, which translates to poor handling characteristics on the road, such as bump steer, and higher wear on components like the ball joints, CV joints and axles.”
The universal principle of matching shocks and springs applies here, too.
“Adding a spacer to a three-quarter-ton pickup can work, as long as the damper we select is valved properly and is the correct length for that increase in spring preload, i.e. the effective spring rate,” he continues. “You don’t want a spacer on the factory shock that’s not designed to control that amount of spring. That will leave the truck kicking and bucking down the trail. Conversely, we don’t ever want to select a damper with too much valving, because the truck will ride very stiffly on the compression side and make life uncomfortable in the vehicle.
“Whether it’s for a leaf spring or a coil spring, it’s important to have a conversation with your installer or manufacturer about the spring rate the valving is set up for.”
Shock setup must always be matched to the tire and tire pressures on the vehicle – and cannot mask the effect of the wrong tire choice.
“When I meet customers who want to upgrade their shocks, the first thing I do is to take a look at the tires on the vehicle,” Grigsby confides. “Unfortunately, tire shops often install improper rolling stock on certain truck platforms, such as a load-range E tire – perhaps a 10-ply tire for a one-ton pickup – on a mid-size truck like a Tacoma. The tire affects the way the dampers work, but in this case, no shock will be able to overcome the tire’s stiffness and weight to produce good ride quality. You need to start with a proper load-range tire and the correct inflation pressure.”
He says that a P-metric tire, as was likely fitted by the factory, should suffice on a mid-size or half-ton truck. If you’re planning extensive hauling or towing within your quarter- or half-ton truck’s capabilities, then a load-range C tire may be enough, with a D representing, “the heaviest I’d want to see. You’d be amazed at the improvements in ride quality to be gained from having the proper tire installed.”
Adding large, drop-down cross members to an independent front suspension (IFS) will lift the truck – but won’t add the wheel travel or ground clearance you may be looking for.
“Wheel travel is determined by the extended and compressed lengths of the shock and the ability to use the shock properly,” says Grigsby. “That means appropriate valving and being paired with the right spring. Without that, you could be outperformed by a setup that has only half the potential travel. It all comes back to matching the spring and the shock.”
If you’re looking to invest in your IFS, then replacing the upper and lower control arms will move the pivot points out to yield greater wheel travel. In off-road racing, Trophy Trucks and Ultra4 trucks take this as far as they can to maximize the travel.
Depending on the type of wheeling you’re doing and having exhausted the easier options, this may be the right approach for you. As Grigsby puts it, “You may find that you’ve put the best shocks you can on that vehicle, but the suspension’s operating envelope is still not acceptable for your use case.
Shop ADS Racing Shocks products by vehicle year, make, and model here.
“You will have to make modifications to the vehicle to yield additional wheel travel beyond what the factory envelope is capable of producing, but there is no one-size-fits-all solution,” he adds. “At ADS, we engineer shocks for long-travel kits and work with the manufacturers to ensure a good match. When the pivot points move out, we must increase the spring rate, which in turn requires additional damping on the rebound side and perhaps some additional compression damping.
“Working within the factory envelope, we also have long-travel replacement shocks that utilize a different upper control arm, tuned for those specific use cases.”
And finally… Twin-damper setups might look great on a heavy-duty pickup, but they do not always outperform a properly specified, single-shock configuration. As usual, it’s all about finding the right balance within the suspension system.
According to Grigsby, “There are few cases where a dual-shock setup will perform better than a single shock, unless those shocks are performing separate duties. One use case where it does work is when a coilover shock has had its valving removed and is primarily acting as a coil carrier. In this scenario, an external bypass shock acts as the damper, and you can adjust that bypass shock without fighting the valving that’s in the coilover.”
Of course, not every truck has space for a dual-shock setup, which is why ADS designed its (IBP) internal bypass MBR (Multi Bypass Ring) coilover shock, which uses one damper to do the job of two. Apart from the above scenario – running a large-bodied bypass shock in combination with a coil carrier – Grigsby believes the IBP MBR will outperform any configuration of dual reservoir-ed or dual-2-inch shocks.
Shop ADS Racing Shocks Direct Fit Race lineup of high-performance shocks here.
Your truck’s suspension is a prime time player in how you use and enjoy your truck. It also a big investment. Avoiding the pitfalls reviewed here will help you make an informed purchase decision.
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