There are different ways to alter the load capacity of your truck. They have all been mentioned in these threads, How they are used and installed will greatly affect the over all performance of your truck.

Your truck's suspension is the culmination of countless hours of engineering, computer wizardry and practical on the road experience. Manufacturers have spent millions of dollars in research, to provide a vehicle that offers the best compromise in ride and load capabilities. And it is just that, a compromise. One conclusion is not the best for everyone's needs.

A suspension has many functions, it has to carry the weight if the vehicle and occupants, provide a pliable platform of varying loads, and allow the tires to remain in contact with the road, regardless of irregularities of the surface.

Trucks typically have a set of springs that provide a variable rate depending on the load. An initial stack supports the truck under an empty or lightly loaded rate. Auxiliary or a secondary stack springs offer additional support as heavy loads are applied.

If additional springs are added to the primary stack, the handling of the vehicle can be adversely affected. This is usually not attempted unless these springs are worn or broken. If additional leaves are added here to increase the load capacity of the truck, they will stiffen the rear suspension. In an unloaded state, the resulting rear suspension can be stiff enough to be effectively without a suspension. With little or no suspension travel, any bump, or rut could literally bounce the rear tires off the pavement. The active suspension and abs would be rendered useless, braking would be severely compromised, and you would have a dangerous, uncomfortable truck to drive.

The overload springs are what should be modified. These are only involved when heavy loads are applied to the suspension. The point where they are activated vary by the weight capacity of your truck. Usually a deflection of four or five inches will be involved. This is the distance your initial suspension travel has to work in day to day driving. By adding varying amount of springs to this secondary stack, your load carrying capacity will increase. There are many companies that offer varying amounts of springs for this purpose.

Air bags and Timbrens are not added to the springs. They are added between the axle and frame. The air bags supplement the original suspension, adding to its capacity as increasing amounts of air pressure are added to the bags. This is accomplished by manual applications using a supplementary air hose, or more complex systems that offer stand alone load leveling systems, with on board compressors, limit switches and all the necessary plumbing.

Timbrens are basically a supplement to the truck's original axle bumper, that prevents the axle from slamming into the frame when it is severely deflected. A Timbren is a hard rubber cylindrical spring that keeps the axle and frame at a predetermined distance. With my truck's secondary springs, the "helpers" just start to aid when enough of a load is applied to make the truck"squat" four or five inches. The Timbrens are installed so that they also touch the suspension components at the same time.

The result is that the initial factory suspension is unchanged, and a normal unweighted ride is effected. When additional weights are added, the suspension will no longer deflect, unlike air bags or overload springs. This result will continue regardless of any additional loading. The only exceptions are two: a structural failure of the suspension components caused by a gross overloading; the failure of the tires caused by the same overloading.

All of these components, the springs, air bags and Timbrens are time tested components. If installed correctly, they will all aid in increasing the load capacity of your truck, greatly increasing its capabilities and handling while loaded.

BOL  Gard