So you bought a ’17 Super Duty—a truck that’s capable of towing 30,000 pounds or more depending on the model you went with—and now it’s time to hook up the fifth-wheel trailer and see what she’ll do. With so much potential present in the current crop of diesel pickups, it’s easy to get swept up in the glorified numbers game of towing and payload ratings. After all, just because a truck is rated to tow or haul a given amount of weight on paper doesn’t mean it will enjoy doing it out in the real world. Excessive tongue weight, poor load positioning, and improper weight distribution can all contribute to a truck that squats, bottoms out, steers and brakes poorly, and suffers from excessive body roll and incorrect headlight aim.
For decades, Air Lift has been helping trucks live up to all of their marketing hype—and the company’s latest air spring system, the LoadLifter 7500 XL, does not disappoint. Designed to support the largest loads on the road, the new Air Lift system brings 7,500 pounds’ worth of load-leveling capacity to the freshest heavy-duty offerings from Ford, Ram, and GM. With a ’17 Ford F-350 being prepped for regular towing duty, we decided to give the LoadLifter 7500 XL a shot. Just three hours later, the complete, bolt-on package was installed and we moved on to outfitting the truck with Air Lift’s WirelessAIR air spring controller. If you plan to move any substantial amount of weight with your ’17 Super Duty, you owe it to yourself to consider Air Lift’s LoadLifter 7500 XL system.
When directly compared to its best-selling LoadLifter 5000 air spring, it’s obvious the Air Lift LoadLifter 7500 XL takes towing to another level. The 7500 XL system is based around massive, 7-inch-diameter (versus 6-inch on the LoadLifter 5000), double-convoluted bellow air springs—the 7500 number referring to the amount of load-leveling capacity of 7,500 pounds, of course. The larger air springs can hold up to 20 percent more air volume over the 5000 series units, and also offer greater leveling strength at lower air pressures.
Built with Goodyear rubber, the 7500 XL air spring is constructed from multiple layers of rubber and cords. Their heavy-duty makeup allows for controlled growth of the air spring, even at lower pressures. Like all of Air Lift’s air springs, the 7500 XL units feature corrosion-resistant, high-strength nylon composite end caps for ultimate longevity under your truck.
To accommodate the larger, 7-inch-diameter air spring, Air Lift had to enlarge the roll plates that reside both above and beneath them. Although the bigger roll plates can create some clearance issues on trucks with aftermarket exhaust systems (more on that later), they offer the air spring additional protection from abrasion and the elements.
Even though it was released in 2017, the LoadLifter 7500 XL system is available for most late-model domestic heavy-duty trucks. This availability includes ’11-’17 Super Dutys, ’11-’17 Chevrolet and GMC HDs, ’03-’13 Ram 2500s, and ’03-’17 Ram 3500s. All required hardware, brackets, and braces are included, along with detailed installation instructions. As mentioned, installing the LoadLifter 7500 XL on our ’17 F-350 consumed just three hours of time.
Prior to installing anything, we first pieced together both air spring assemblies. The lower bracket cups (shown) fasten to the lower air spring bracket plates and ride on the truck’s factory striker plate (bumpstop perch). The upper air spring brackets install after the roll plates have been fastened to the top of the air spring. All brackets and braces are made from 1/4-inch-thick steel.
No one wants to battle an air leak with their air spring system, so it only makes sense that Air Lift goes the extra mile to reduce the chances of that happening. The company conveniently pre-wraps the threads of the supplied swivel elbow fittings with Teflon tape. Although it wasn’t necessary, we added a coat of sealant on top of the pre-wrapped threads for ultimate peace of mind.
Due to three different rear axles being offered between Ford’s ’17 model F-250, F-350, and F-450, Air Lift supplies three different lower leg adapters. The lower leg adapter spans from the axletube to the lower air spring bracket and adds considerable support to the air spring assemblies. Note that the air spring assembly and lower leg adapter are shown upside down in this photo.
If you’re not sure which rear axle you have, you can check its diameter with a caliper. In most cases, a diesel-powered ’17 F-250 void of the HD tow package will possess a 10.5-inch Sterling with a 3.5-inch-diameter axletube; a single rear wheel F-350 equipped with the Dana M275 will have a 4-inch axletube (as is the case in this article); and dual rear wheel F-350 and F-450s graced with the massive Dana M300 will feature a 4.5-inch axletube.
Once the top mounting bracket is secured to the truck’s frame (using existing holes), each air spring assembly can be positioned in place, with the lower bracket flush up against the factory lift block. The lower air spring brackets have flanges built into them, which effectively lock around the factory 3/4-inch-diameter U-bolts. From there, one supplied U-bolt ties the air spring assembly to the lift block horizontally, while a second U-bolt clamps the air spring assembly to the axletube vertically. Also notice that the lower leg adapter is in place between the Dana M275 axletube and the lower air spring bracket in this photo (arrow).
Using the air line that’s supplied in the LoadLifter 7500 XL kit, we used compressed air to inflate and ultimately raise the height of the air springs in order to attach them to the frame-mounted upper chassis brackets. Otherwise (and because we were performing the install with the truck on a two-post lift) we would’ve had to lower the truck down in order to compress the suspension. Just a little labor- and time-saving trick we’ve picked up on after having been around several air spring installs.
With aftermarket exhaust systems being so popular these days, it’s important to note that the LoadLifter 7500 XL might not be compatible with your truck if it’s equipped with a larger-diameter exhaust. At least in the case of our ’17 F-350, the passenger-side top roll plate (required to accommodate the larger, 7-inch air spring) barely cleared the truck’s 5-inch-diameter exhaust system.
For added support and stability atop the air spring assemblies, Air Lift supplies frame braces. The 1/4-inch-thick brace shown here installs above the passenger-side air spring assembly using existing holes in the frame and by way of two 5/8-inch Grade 8 bolts measuring 4.5 inches in length. On trucks with the factory installed fifth-wheel hitch option, installing the passenger-side brace requires removal of the fifth-wheel bracket and hardware.
With both air spring assemblies in place, the final torque specs were administered for all fasteners. From there, several loose ends were tied up, including anchoring the axle vent tube to a soft brake line to keep it from ever coming into contact with the driver-side air spring assembly.
What could be better than installing the heaviest duty air spring system on the market? How about being able to control it wirelessly with Air Lift’s cutting edge WirelessAIR system? Complete with a compact, onboard air compressor (which we mounted in front of the fuel tank, along the inside of the framerail), the universal WirelessAIR package comes with air lines, a wiring harness, and controller.
An intricate piece of the WirelessAIR system is the air manifold. It’s capable of keeping air pressure contained in the springs within 3 psi of each other for precise load-leveling control. The air manifold only requires a simple, 15-amp source to power it, and the supplied wiring harness plugs right in. And thanks to being weather-resistant and incorporating a filter than drains automatically, the air manifold is virtually maintenance free.
Taking convenience to a whole new level, the handheld WirelessAIR controller allows you to adjust air pressure in increments of 1 to 10 psi, and for each individual air spring. Adjustments can be made outside the truck, in the comfort of the cab, and you can even fine-tune your ride quality on the fly. The backlit LCD screen is easy to read and warns you of any air leaks or compressor issues.