Lift kit

A suspension lift is a modification to a vehicle to raise the ride height. It is usually done for the practical purpose of improving the off road performance of SUVs or trucks and other off-road vehicles, or for cosmetic purposes. Suspension lifts can enable steeper approach, departure, and breakover angles, higher ground clearance, and helps accommodate larger wheels and tires. Due to the raised center of gravity, maximum safe operating angles can be reduced and roadholding is often significantly impaired.

A lift kit is an aftermarket product package with the parts needed to lift a specific model of vehicle, typically with instructions and customer support. Some kits may have only critical or difficult to obtain parts, needing generic or off the shelf hardware and parts to complete the lift. Some lifts need only a few parts, like lift blocks, the spacers placed between the axles and leaf springs, and coil spring/strut spacers and extended shocks, and special driveshafts, axles, and more. More extensive lifts require many new suspension, steering, and drivetrain parts, such as replacement control arms, trailing arms, custom four-link systems, and drive shafts. These changes may be necessary because raising the vehicle's ride height can impact drive shaft length, steering geometry, and brake lines. Legality is often an issue when installing suspension lifts, as many jurisdictions have varying laws on vehicle ride height and placement of lights and bumpers.

Many trucks are supported by leaf spring suspensions. Leaf springs offer exceptional articulation, a large payload and can take a substantial amount of abuse. With the correct methods they can be modified to help a vehicle carry more weight, have better articulation or to fit large oversized tires. Some vehicles may be equipped with front and rear leaf springs or just rear leaf springs with independent front suspension.

Some methods of lifting are good for the rear, but not for the front, such as lifting blocks. Lifting the rear with blocks is a common way to achieve the desired height. This is done by installing a block, of the desired height of lift, in between the leaf spring and leaf spring perch and installing longer U-bolts. It is a bad method for the front primarily because of safety issues while braking. When braking, the front wheels create the majority of the braking force. The block moves this lateral force, caused by braking, higher above the axle than it did in the stock form. This can cause the block to become displaced from its location and result in total loss of control.

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Wikipedia