By Dan Sanchez for PickupTrucks.com
It's common for truck owners to lower their vehicle’s suspension system a few inches for a sporty look, or they go to the extreme and lay the frame on the ground to create a wild custom show vehicle.
You can lower a full-size or midsize pickup in a variety of ways that affect its appearance, handling, towing and cargo capacity. We’ve outlined the most common methods and best practices so that you gain a better understanding of the techniques and what best suits the look and performance you want to achieve.
Manufacturers make it easy to lower your vehicle by offering a complete kit. This example shows a two-inch front drop with coil springs and a four-inch rear drop using new leaf springs, shackles and hangars.
An aftermarket set of coil springs is a great way to lower your truck’s suspension as much as two inches. Some trucks use coils at the rear, so look for a complete kit from the same manufacturer. The best choice is to use progressive-rate springs made from high-quality steel, to avoid spring sag over time. Some performance coils will also improve handling and lower the stance by one-and-a-half to two inches.
Cutting your factory coils may sound like a less expensive alternative but it’s not recommended because it can change the spring’s compression rate and can lead to a bouncy ride. A spring that lowers ride height more than two inches may be a bad idea. The right coils will lend a smooth ride and won’t affect the overall cargo capacity of your pickup when you need moderate lowering.
Coils can be combined with other lowering products when more lowering is desired.
Drop spindles are very popular. Some four-wheel-drive vehicles can be lowered this way, too.
Drop spindles are probably one of the best ways to lower your vehicle properly by two or three inches without affecting the ride quality or factory suspension geometry. It’s worth paying more for a high-quality spindle from a reputable manufacturer; cheaper spindles are known to crack and shear. Combining drop spindles with a two-inch lowering coil can give you up to four inches of drop.
Lower control arms are another great method to lower your truck’s front end properly. The lower coil spring pocket brings down the vehicle’s ride height, while the rest of the suspension remains in the stock position. These can be combined with lowering springs for a four-inch front drop.
Tubular upper and lower control arms replace the factory wishbones in the front of your truck. A new lower arm will have a deeper coil spring pocket. This effectively lowers the vehicle two or three inches and maintains proper ball joint angles and a smooth ride.
If you’re going to use low-profile tires, it’s important that the lower control arm spring pocket doesn’t fall below the vehicle’s scrub-line, which is the lowest part of the vehicle that will make contact with the pavement should the tire go flat.
A new upper A-arm will compensate for the negative camber (top of tire points in toward the body) that occurs when the vehicle is lowered. Both matched sets of arms are necessary for proper operation and suspension alignment and are typically used with shorter coil springs, air springs and/or drop spindles to get your truck even lower.
Air Springs (bags)
Airbags or air springs come in a variety of kits. This one attaches to the truck frame and axle to lower the rear five to six inches. Others systems can be customized to lower the vehicle all the way to the frame.
Air springs or airbags offer unique advantages for lowering a vehicle. They can be retrofitted just about anywhere, front or rear, to provide a very low stance when deflated. Then they can be inflated with an onboard compressor and a system of actuators, switches and hoses to drive the truck at a normal ride height.
Air springs provide the most options for a moderate to extreme drop. Usually they can simply replace your factory coil springs in the front and leaf springs at the rear. Extreme lowering, where the truck rests on the frame, requires more customizing and should left to a professional. One of the most important aspects of an air spring suspension is to set a normal ride height for driving and set the vehicle’s alignment for that height. This will avoid excessive tire and suspension component wear.
Depending on how low you want to go, air springs can be set into custom-built A-arms in the front to lay the frame on the ground. Likewise for the rear, a custom rear air-spring frame that protrudes through the bed can be built to lay the rear suspension and frame on the ground. Because of all this, you’ll have a great-looking custom truck, but you’ll lose any or all of its cargo-carrying capabilities. This should be done only if you’re contemplating creating a show-winning vehicle.
Popularized by lowriders, hydraulic systems work like air springs but use hydraulic fluid to fill up solid cylinders that replace the truck’s coil springs, shocks and leaf springs. This system requires a sophisticated network of switches, solenoids, hydraulic lines, tank and a hydraulic pump to operate successfully. You’ll need to hire a well-known custom installer because of the extensive cutting and welding. Using hydraulics will eliminate any cargo or towing capacity.
Leaf Spring Eye Hangars
Most trucks use leaf springs at the rear because of they hold up to extra cargo capacity. Many truck owners replace the factory leaf spring mounts — also called hangars and shackles — to lower the rear one-and-a-half to two inches. This requires drilling out or cutting the factory shackles from the frame and bolting on new ones. This method works extremely well and is often combined with other products to achieve a lower stance. This method also works great to level out the ride of your truck from front to rear, and because you’re still using the factory spring, you won’t lose any towing or cargo capacity.
Lowering Leaf Springs
Lowering leaf springs are a great way to drop the rear of your truck. They result in a great ride, but you’ll sacrifice some of the overall cargo and tongue weight capability.
For the rear of your truck, you can get leaf springs that lower the ride height two to three inches. If you combine those springs with new lowering spring eye hangars, the rear can drop four inches. These springs have noticeably less arch and work well for providing a comfortable ride. The drawback is less overall cargo and tongue weight capacity because fewer leaves are used in the spring and they typically don’t include a helper spring. Many truck owners, though, will use an airbag helper spring that sits on top of the leaf spring to restore some of the lost cargo capacity and raise the rear of the truck to compensate for a heavy load or trailer.
Leaf Spring Blocks
Lowering blocks are common for leveling or extreme applications. The best blocks are made of steel and should include a shim to correct the differential’s pinion angle.
Blocks have been one of most popular ways to lower the rear of pickup trucks anywhere from one to three inches. Many lowering kits include leaf spring blocks inserted between the axle and the leaf spring. The absolute best blocks to use are steel units with a built-in pinion angle correction. They actually look more like a wedge than a square block, or the blocks can come with a wedge that can be added to provide the proper pinion angle. In most instances, blocks are used with leaf spring hangars to lower the rear of the vehicle up to four inches. It’s important to use high-quality U-bolts when lowering with blocks.
For extreme lowering of the rear — five to eight inches — flip kits tend to be a necessary component to provide enough travel and clearance between the axle and the frame. They flip the position of the leaf spring and axle so that the springs move from beneath the axle to the top. A proper high-quality flip kit will have a proper axle locator that positions the rear axle slightly forward and maintains the proper pinion angle geometry of the differential.
Most flip kits will also require that the rear portion of the frame be C-notched for added up/down travel of the axle. The notch is reinforced with a steel frame-support bracket that should be drilled and bolted in place. Welding can often weaken tempered steel, from which most truck frames are made. When flipping the axle and leaf spring, it’s important to consider shorter shocks or shock extensions. These keep the shocks at a more vertical angle to provide better operation and a smooth ride.
Because many trucks use a center carrier bearing for a two-piece driveshaft, vibrations can occur. To cure this, many flip kits come with a spacer to lower the center carrier bearing that places the driveshaft in the proper angle.
How Low Do I Go?
This Dodge is an extreme example of a custom airbag system with a C-notch on the frame. This allows truck’s frame to rest on the ground.
With various products and methods available for lowering your truck, here are some of the more popular procedures that can help you decide what might work best for your application:
Many manufacturers offer complete systems that take the guesswork out of adding the right components to lower your pickup. Using shorter shock absorbers or shock mount extensions will also improve the ride quality. If you’re interested in performance handling, adding a set of performance anti-sway bars may help, too. Also consider the correct load rating of the tire you will use. Trucks are still heavy, and various tire manufacturers sell lower-profile tires that will complement your lowered pickup also feature the correct load rating for a safe ride.