Leveling kit or lift kit? What changes on a diesel truck

Most diesel trucks leave the factory sitting lower in the front than in the back. The rake is there on purpose. When you hitch a heavy trailer or load the bed, the rear squats and the truck comes out close to level.

A leveling kit or a lift kit changes that, along with a few other things. Here's what to know before you pick one.

What a leveling kit does

A leveling kit raises the front to match the rear, usually by a couple of inches. It's the smaller job. The truck sits level, and there's room for a slightly bigger tire.

The tradeoff shows up when you tow. With the rake gone, a heavy trailer pushes the rear down and points the nose up, and the headlights aim high. If you pull a big trailer often, bring that up before the truck gets leveled.

What a lift kit does

A lift kit raises the whole truck and makes room for bigger tires. It's a bigger job with more parts, and what's involved depends on how much lift you want and what kind of front end the truck has.

• A Duramax has independent front suspension. Lifting it changes the angles on the front axle shafts, and the kit has to account for that.
• A four-wheel-drive Ram or Super Duty has a solid front axle. Lifting it changes the track bar angle and the caster, which decide how straight the truck tracks and how the steering feels.

What to check after either one

• The truck needs an alignment.
• Bigger tires throw off the speedometer, so it needs recalibrating.
• Bigger, heavier tires make the truck work harder to get a load moving. You'll feel it most when you tow.
• A taller truck puts the hitch higher. A drop hitch brings the trailer back to level.

Death wobble on a solid axle

Death wobble is a violent shake in the front end, usually set off by a bump at speed, that doesn't stop until you slow way down. It happens on solid-axle trucks, and a lift and big tires can make it more likely. The usual causes are worn or loose front-end parts, starting with the track bar and its bushings, then ball joints and tie rod ends.

A steering stabilizer can hide it for a while. It won't fix the worn part underneath. If your truck has done it once, get the front end checked before it happens again on the interstate.

What we do

We install leveling and lift kits on Duramax, Power Stroke and Cummins trucks, and we fix the worn front-end parts behind loose steering and wobble. Tell us what you want the truck to look like and what it has to do, towing included, and we'll help you pick the setup.