Choosing the Right Suspension Kit for Your Truck and Trailer

(Air Bags, SumoSprings, Timbren—What's the Difference?)

If you're here, you're probably not happy with your towing experience. You might be experiencing a number of unpleasant situations, including body roll when turning, difficulty steering and braking, and your vehicle feeling as stiff as a board every time you hit a bump or pothole.

Fortunately, these scary situations have a remedy: suspension enhancement. Adding suspension enhancement to your truck will improve almost every aspect of your towing experience. By now you know for a fact that this is not a want, but a need.

And if you haven't yet experienced any of these scary situations, we recommend getting a suspension kit before you even purchase that travel trailer or fifth-wheel. Air bag suspension will help whenever you add weight to the rear of your vehicle, so don't wait until your towing experience starts to feel uneasy to invest in a kit.

So, how do you choose the right suspension kit for your truck and trailer? What's the difference between Sumo Springs and Air Bags? Timbren vs Sumo Springs? Helper Springs vs Air Bags? Which type of suspension is best? If you've hit a wall and you're not sure where to go from here, you're in the right spot.

Today you'll get the full run-down on improving your truck's suspension and how to choose the perfect enhancement kit.

Note: Suspension kits do not increase your towing capacity.

If your truck is only rated for 1,000 lbs of tongue weight, getting a spring with a 5,000 lb capacity will still not allow you to exceed 1,000 lbs. Air bag suspension is designed to supplement and enhance your vehicle's suspension while towing or hauling—it will keep your luxury tow vehicle having that luxury experience, even with a massive fifth wheel hooked up, but it won't let you haul a heavier fifth wheel than your truck alone allows.

Vehicle's rear sags when hooked up to a trailer/fifth wheel
You experience body roll when turning corners
Vehicle's front end is elevated due to rear sagging, which causes headlights to blind oncoming vehicles, and causes difficulty steering and braking (feels like you're floating)
Vehicle feels very rigid when you drive over bumps and potholes
You want to extend the life of your vehicle's suspension and reduce tire wear

Air Springs vs Jounce-Style Springs

The most common options you'll see for enhancing truck suspension are air springs and jounce-style springs. These include all those names you've probably heard: Firestone, Timbren, SuperSprings. These two styles have several similarities—both are custom-fit, bolt-on applications (typically this means you won't have to drill into your vehicle's frame). When used correctly, both have the same outcome: a level truck, a smoother ride, better stabilization, and a reduction of the wear and tear on your vehicle and trailer.

The main difference between these two styles is their adjustability. Since air springs rely on air (as I'm sure you could've guessed), you can inflate or deflate them as needed depending on the load you're hauling. Jounce-style springs, on the other hand, have the benefit of needing zero maintenance (no PSI adjustments needed), but they're not adjustable. They are always there and ready to engage when the load on your vehicle is enough to engage them. Generally speaking, air springs are best for inconsistent loads (switching trailers, riding loaded vs unloaded). Jounce springs are best if you're always loaded with more or less the same amount of weight.

You can also find kits like the Air Lift LoadLifter Ultimate series that combine the adjustability of air springs with the ride comfort improvements of jounce springs.

Let's dig a little deeper into these common types of suspension enhancement.

Air Spring Suspension

This is for you if:

If you're a frequent and/or heavy-duty tower who wants high-quality springs customizable for each load you haul, air springs are for you.

Air springs can be adjusted as needed via an air compressor and allow for different loads each time you haul. If you're hauling a big load one day, you can add air pressure to your springs to keep your truck level. Then the next day when you're pulling your lightest trailer (or nothing at all), you can deflate them for the best handling.

Using Air Compressors

Most air spring kits include a line kit so that you can install the inflation valves (one for each spring), in a convenient spot - typically on the bumper. This is a great feature for those of you who are towing your fifth wheel or camper only a few times a year and don't mind manually inflating your air springs as needed.

However, if you tow quite frequently and with different loads, we highly recommend getting an on-board air compressor kit that installs under your vehicle. These will save you a lot of time and stress by allowing you to monitor your air pressure and inflate your springs at the flip of a switch the moment you notice them getting low. Air springs can also be adjusted separately to compensate for off-center loads with the use of a dual path compressor. This is great for all you workaholics who are always hauling different types of cargo in your work truck.

Types of Air Springs

There are two types of air springs: air helper springs and coil air springs.

Air Bag Helper Springs

Air bag helper springs are the best option for all you heavy-duty towers I mentioned above. They're most commonly seen on full-size pickup trucks, service trucks, and other trucks towing heavy-duty loads. These springs have a heavy-duty rubber construction and are installed between your vehicle's frame and its rear suspension. The capacity for air bag helper springs ranges from 1,000 lbs to 7,500 lbs. They do an exceptional, and arguably the best job at improving your vehicle's stability, ride quality, and extending the life of its suspension and moving parts.

Air bag helper springs can have a few different designs, all depending on what vehicle you have. The two most popular heavy-duty air springs are Firestone's Double Convoluted (also referred to as "double cheeseburgers"), and Air Lift's LoadLifter air helper springs.

Air bag helper springs

Coil-Style Air Springs

If you're not a frequent or heavy-duty tower, and maybe you just like to take your boat trailer or teardrop trailer out a few times a year, coil-style air springs are meant for you. These are commonly seen on lighter-duty vehicles such as SUVs and vans. Coil air springs have a much lower capacity rating, usually up to 1,000 lbs, and are designed to support your existing rear coil spring while you're towing or hauling.

These springs, usually made out of a polyurethane construction, are designed to fit right inside your coil springs. Even though these air springs are made for smaller vehicles, hauling much lighter loads than air bag helper springs, they still greatly reduce the strain on your vehicle's suspension and will improve your overall ride quality. Both Firestone and Air Lift offer a variety of excellent options for custom-fit coil-style air springs.

Coil-style air springs

Jounce Spring Suspension

This is for you if:

If you're a tower who hauls a relatively consistent load and doesn't need the adjustability of air springs, you can save money by purchasing jounce-style springs instead.

Just like air springs, jounce springs help level out your vehicle when towing, absorb bumps and shock, and increase your vehicle's stability. The main difference is that they rely on the composition of the spring, rather than air pressure, to enhance your ride.

On one hand, this means jounce springs have a big added benefit: they require zero maintenance (yep, zero), since you'll never have to inflate or deflate them. You can just install them once and forget about them. On the other hand, this means you can't inflate or deflate them, so they can't be adjusted for different loads. (This means if you're riding empty and hit a bump, they may engage and give you a bit of a jolt!)

So how do jounce springs work exactly? Because jounce springs don't make constant contact with your vehicle's frame, they depend on the amount of weight that you put behind your rear axle in order to function. So the more weight you add to the back of your truck (up to a certain point, of course), the better these springs perform. They are typically made of heavy-duty rubber (like these Timbren springs) or a durable microcellular urethane (like these SumoSprings). Both materials are comparable and feature a flexible, durable construction.

Types of Jounce Springs

There are two types of jounce springs: those that replace your factory bump stops, and those that sit above the leaf spring.

The two brands you'll most often see associated with jounce springs are Timbren and SuperSprings. Overall, both brands offer high-quality, very effective jounce springs. However, to find out who takes the cake, check out our Best Air Bag Suspension article to discover which one wins the title.

Springs that Replace Your Factory Bump Stops

The brand best known for creating this type of jounce spring is Timbren. These jounce springs are heavy-duty, high-quality, hollow rubber springs. They do an excellent job at providing additional support and acting as shock absorbers. These are the simplest bolt-on application of all the air bag suspension options, usually taking about 20-30 minutes for the entire install.

However, Timbrens replace your smaller, factory bumpstop with a larger bumpstop. Because of this, they engage sooner when you travel over bumps, which can make for a rough ride when unloaded.

Springs that Sit above the Leaf Spring

This type of jounce spring installs in the same location as an air spring, and SumoSprings' jounce springs are one of the best of their kind. Their springs are made out of a durable microcellular urethane, which work in almost any temperature, and they also resist damage caused by oils, road salts, and UV rays.

These springs also do a great job at supporting heavy loads, absorbing bumps and shocks, and minimizing sway. When your vehicle is loaded, these jounce springs can compress by as much as 80 percent for extra support. They are also a simple, bolt-on application, which can take about 30 minutes to an hour to install.

Other Types of Suspension Enhancement

Aside from air springs and jounce springs, there are two other types of suspension enhancement. Both use steel which is clamped to the vehicle's factory suspension. Both types are designed to provide almost all of the same benefits as air bag suspension, including reducing sway, improving steering and handling, and leveling out your vehicle. The two types of steel suspension enhancement are leaf spring enhancement and overload pads.

Leaf spring enhancement install over your vehicle's existing leaf spring, around the factory U-bolts. This type of suspension enhancement actively strengthens the leaf springs to improve your ride quality, with or without a load.

Overload pads, on the other hand, bolt onto the ends of each leaf spring, on the overload spring. They are also custom-fit to your vehicle. Overload pads help to evenly distribute extra weight and reduce side-to-side sway and body roll. Torklift's StableLoad overload springs are very effective on their own at improving your ride quality, but they can also be a great addition to your existing air bag suspension.