Why Your Suspension Lift Kit Components Might Seem Too Thin

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Posted on: 24-07-2015

Once you purchase a Suspension Lift Kit, you may notice that some of the components are not as thick as the lift has been advertised and that you were hoping to achieve. Fret not! In many situations involving vehicles with independent suspension, the thickness of the spacer is not directly related to the amount of lift provided. Let’s take a look a few suspension designs to see why this happens.

Solid Axles

With a solid axle, the amount of lift is equal to the thickness of the lift spacer.

When lifting a vehicle equipped with a solid axle (also known as a live or beam axle), both wheels are rigidly connected to each other and move, relative to the vehicle, as a single unit. Regardless of whether the axle is supported by leaf springs or coil springs, the amount of lift gained will be identical to the thickness of the spacer or block installed. For example, when 1.5” suspension lift kits are installed on beam axle-equipped trucks, the trucks will be lifted 1.5”.

Independent Suspensions

With an independent suspension, the amount of lift can be significantly greater than the thickness of the lift spacer.

Calculating the amount of lift to expect for an independent suspension application can be a little less straightforward. Independent suspension designs typically consist of at least one control arm, the inside of which is secured to the frame while the outside is attached to the wheel. It is supported by a spring or strut mounted someplace between the wheel and the frame. Suspension travel is accomplished by the control arm pivoting at the point where it is mounted to the frame. Since the wheel is mounted farther from the control arm pivot than the strut is, it experiences a longer travel than the strut does. For example, installing a 1.5” thick strut spacer on independently suspended vehicles can act as 3” lift kits.

The good news is that all of Supreme Suspensions’ lift and leveling kits are advertised by the amount of lift you can expect, rather than the thickness of the spacer. This allows the consumer to purchase a lift or leveling kit without having to account for the geometry of an independent suspension. It is, however, important to remember that many lift spacers may not be as thick as the amount of lift that they provide.