Pickup Truck Suspension Systems Explained

Pickup Truck Suspension Systems
2009 Dodge Ram Rear Coil Suspension. The Chrysler Group

Whether you own a Dodge Ram 4x4 or a compact Toyota Tacoma, suspension is an important part of your pickup truck's overall performance. Comprised of a series of springs and shock absorbers, a suspension system is designed to cushion both the driver and the vehicle from potentially uncomfortable and/or hazardous road conditions.

How a Suspension System Works

A suspension system is traditionally created with springs that absorb part of the shock when you hit a bump, allowing the tires and axle to move independently and softening the impact to the rest of the truck.

If the truck's axle was attached directly to the frame, without any type of suspension springs, you'd feel every little crack in the road because nothing would be in place to absorb the impact. In fact, you wouldn't be able to control the truck, because its tires would bounce off the ground whenever you hit a bump.

Leaf Spring Suspension System

One of the earliest forms of suspension, a leaf spring system is made up of one or more long, arched pieces of steel that are designed to flex when necessary (like when you hit a bump or put a load in the truck bed), but with the ability to return to the arch's original shape.

One end of a leaf spring is attached to the frame, and the other end is attached to a shackle that can move, allowing the spring's overall length to vary as far as its arch flexes (when carrying a load or traveling over bumps).

Adding more leaf springs allows the system to support more weight, which is why heavier duty trucks have multiple layers of leaf springs.

Leaf Spring Comfort Factor

A single leaf spring typically doesn't support as heavy of a load as multiples, but it flexes more freely with the ups and downs of a road, delivering a fairly comfortable ride.

A stack of leaf springs supports a heavier load by making it more difficult for the main leaf to flex and preventing the truck from bottoming out. The trade-off is a stiffer ride when the truck bed is empty, because, without a load, very little flex takes place.

Coil Spring Suspension Systems

Coil spring suspension systems are used on the front of most trucks and on the front and back of most cars. Systems typically have a single coil on each side of the vehicle. The coil moves more freely than a leaf spring setup, offering more give and a comfortable ride.

Rear Suspension Systems

Manufacturers have traditionally used leaf springs for pickup truck rear suspensions because they felt that type of system offered the best support for heavy loads.

Dodge broke from tradition with its 2009 Ram 1500s, installing a coil spring suspension system on the rear with promises that the system would carry a load without compromising comfort. The set up has proved to be highly successful.