Suspension Load-Leveling Systems for TowingPosted in How To on October 1, 2001 Comment (0)
Have you ever loaded the back of your pickup or SUV with all your gear and then noticed that the rear end has hunkered down? Maybe you then tried to tow a trailer with your trail rig on it. The next thing you knew, the back end of your tow rig was almost dragging.
If you haven't yet experienced this woe, you still might. And if you have, then you know the feeling of fear and dread that riding nose-high instills in a driver. The dread is there because as the back end of a truck is pushed down, and the front is forced up, things get hard to control. Steering control is reduced and the braking ability is adversely affected. Further, you'll find that the trailer is unstable. If you tow a lot, as we do, you know that sometimes you can move your trail rig around on the trailer to help to offset this problem. But only sometimes. Usually the trouble isn't too much tongue weight, but rather too much trailer weight overall.
For things to work properly when towing a trailer, you should load your trailer so that the tongue weight is 10 to 15 percent of the total weight. This means that if your trailer and trail-rig combination weighs 8,000 pounds, for instance, you should have between 800 to 1,200 pounds of tongue weight. Now with an average of 1,000 pounds pushing down on the very back of your truck, you're sure to get some settling of the suspension. When you add the weight of gear to your rig too, well, you see the problem. The solution is to stiffen the rear spring rate. Yet you don't want this stiff suspension when you’re driving around town unloaded.
There are two ways to overcome the problem of a suspension that is occasionally too soft when you load your truck or SUV for the long haul. One is to install helper leafs that only come into play when the suspension is loaded. When you choose this solution, an extra spring and stop are added to the rear suspension and when the load compresses the stock springs far enough, you begin to use the helper leaves. The trouble is, your truck was built to handle best when it sits level. By its very nature, this solution guarantees you’ll ride a little nose-high no matter what. A better option is an airbag load-leveler system.
Airbag systems can be mounted to almost any truck and have several advantages over other methods of load-leveling. First of all, you'll be riding on a cushion of air just like those city buses and large moving vans do. This means a smoother ride than any spring system can offer when loaded. In addition, you can usually fill the airbags enough to bring your truck back to a level pre-loaded height for the best handling. Further, if you are forced to load the bed of your truck unevenly, you can level the load side-to-side if you need to (for this option you need to have a split-air system).
Airbag load-leveling systems are available in a wide range of configurations and from several sources. However, when you get down to the basics, you really have two types of airbags . There's the in-coil bag, and the outside-the-coil bag. In-coil airbags are just what they sound like pressure airbags that go inside the coil springs of your rig's rear suspension. Of course, if you have leaf springs you can use the out-of-coil airbags that mount with brackets either to the side of the frame or between the axle and the frame. Both serve the same function and you'll be happy with whichever system your rig's rear-suspension system requires. Installation is simple in most cases and usually can be done in less than a day.
As a plus, you'll get an air compressor and a storage tank for your truck that can be used to fill tires when, for instance, you have to get on the highway after towing down a sand wash. If you want to, you can even install a compressor to match the one on your trail rig so you'll have a spare in emergencies. Oh, you're looking for an air system for your trail rig? We've got you covered. Just check & Give Me Air; (June '01) for information on 12-volt air sources for your trail rig.