Handy air springs take the squat and wallow out of hauling heavier loads
It looks like a big white tanker rolling from side-to-side in heavy seas while kicking up a brown spray from the stern. In reality it’s an excavation company’s four-wheel-drive F-350 service truck lumbering along a dusty dirt access road of a highway-widening project.
I can imagine what it’s like behind the wheel hustling toward a broken-down piece of equipment while fighting the buck and sway of five tons of Super Crew loaded down with a compressor, welder, tools, lubes and spare parts. Please pass the Dramamine.
Heavily laden pickups are common around smaller construction and landscaping companies.Older pickups are more common than new.
Older suspensions, combined with years of jobsite wear and tear, mean less than optimal ride and handling under heavier loads and towing tasks.
But that doesn’t mean the driver has to be saddled with poor stability and control. Sometimes all that’s needed in those instances is a little assist from “overload” or helper springs to make the situation better.
Stabilize Heavy loads
Helper springs are easy to install and low on the cost ladder. But they don’t increase a pickup’s load carrying or towing capacity.
“Airbags and helper springs can be useful accessories when used in the proper way,” says Larry Sorenson, the engineering manager for B&W Trailer Hitches. “They can help stabilize heavy tongue weights and keep the vehicle level when towing.
“Some customers feel like they can increase their pickup’s tow rating with overload springs, but that’s not true,” warns Sorenson. “The truck manufacturer has calculated the tow rating based partly on suspension, but also based on brakes and drive train.”
Robert Krouse, General Motors North America trailering engineer and chairman of the SAE Tow Vehicle Trailer Rating Committee adds, “Many factors such as frame, tires, springs, shock absorbers, hitch, steering system, brakes and axle assembly, etc., contribute to these [vehicle manufacturer] ratings.”
That’s why manufacturers set very specific limitations noted in the owner’s manual on such things as front/rear gross axle weights, Gross Vehicle Weight Ratings (GVWR), Gross Combined Vehicle Weight Ratings (GCVWR), Trailer Weight Ratings (TWR) and trailer tongue weight. Exceed any of those limits and vehicle handling and stability suffer.
So, if your pickup feels like it’s overloaded, it probably is; and adding helper springs doesn’t change that situation.
What helper springs do, however, is firm up the ride and handling of a truck to make it feel and appear like it’s carrying a lighter load. They also help maintain good body-to-tire clearance in off-pavement situations.
“The correct helper spring will provide a firmer, more performance-oriented ride, but not harsh,” says David Wheeler, Hellwig Products’ suspension engineer. “Many new pickups are very softly sprung and the correct helper springs will improve performance when lightly loaded by reducing spring wrap-up under acceleration or braking.
“Helper springs, of course, really help to level the vehicle when it is loaded and prevent the suspension from bottoming out and wallowing,” adds Wheeler.
Helper springs come in a variety of configurations. The most common version, like those offered by Hellwig and SuperSprings, is a partial- or full-leaf-spring style that attaches to the rear spring packs of the truck.
The helper spring comes into play when the stock spring flattens to some point under load and puts pressure on the helper. The more the main springs flex, the more the helper leaf resists, squat and wallow. Some helper springs can be adjusted and all are virtually maintenance-free.
Another variety uses air bags between the axle and frame. The air bags can be inflated/deflated to provide additional support according to the load.
Some air-helper spring systems, such as those made by Firestone Industrial Products and Hellwig, are fully automatic or allow side-to-side adjustments and in-cab adjustability on the fly.
Air helper systems are more expensive than the conventional leaf-spring style, but they offer far greater adjustability with little or no effect on stock ride/handling.
There’s also a new version of helper springs made from advanced high-grade, closed-cell polyurethane foam, which acts like a big variable-rate bump stop. SuperSprings’ SumoSprings (photo at the left), which are attached to both the frame and axle housing, compress as the axle moves upward, firming up the ride and handling.
Choosing which helper-spring style to use is totally dependent on your pickup’s age, use, suspension design, and how much you want to invest in its ride and handling.
If your pickup is brand new, for instance, the latest suspension technology under its frame may not need any help.
But if it’s an older pickup, having those handy helpers sitting above the rear leafs may be just what the suspension doctor ordered.
B&W Trailer Hitches; turnoverball.com
Firestone Industrial Products; firestoneindustrial.com/riderite
Voiding the warranty just by the addition of aftermarket parts is more manufacturer/dealer scare than legality. The Magnuson-Moss Warranty Act of 1975 says that the use of an aftermarket part alone is not cause for denying the warranty.
However, the law’s protection does not extend to aftermarket parts in situations where such parts actually caused the damage being claimed under the warranty.
So don’t be afraid to upgrade/accessorize your new pickup. You have every right to do so. Just read the warranty information of the part(s) you want to install before doing so.