4×4 Lift Blocks: Big Lift or Big Trouble?

Lift blocks have long been a popular and cheap way to gain clearance for larger tires on leaf-spring suspensions. However, they do have some drawbacks, and depending on the situation they can be pretty serious. Before you lift your truck using blocks in the rear, ask around and get opinions from some of the veteran wheelers of the area. They have likely encountered them firsthand, and will surely have something to say about them.

Lift blocks are just that – blocks of steel that go between the leaf springs and the axle, creating height. Very simple in design and cheap to purchase, it is no wonder these blocks can be found under so many big trucks! Leaf springs of the same height would be very expensive.

Keep in mind that the larger the distance from your leaf springs to the axle, the greater the leverage on the springs. This creates a phenomenon known as “axle wrap”, when the axle wants to actually twist away from the springs, turning them into an S-shape. This can cause the truck to bounce up and down violently, which becomes dangerous on hill climbs and on the highway, too.

NEVER install lift blocks on the front end of a solid-axle vehicle. Don’t think about it, don’t joke about it, just never ever do it. The reasoning behind this has safety in mind, and is a cardinal rule. If there are blocks on the front end and you need to turn while under power in four-wheel drive, all hell can break lose with steering components when that axle decides to start hopping and twisting.

Lift blocks are relatively easy to install and can be done in the driveway with basic hand tools and a good jack. Invite some friends over, BBQ some burgers and dogs and make a day of it. Just make sure you re-torque everything back to the manufacturer’s specs, and check on the U-bolts every few days to make sure they are staying tight.

Lifting a vehicle with blocks actually lowers the axle, allowing for more space between the rig and the tires. Make sure your brake lines are long enough to compensate for the increased space, and that they are in good shape. I do not recommend going over four inches on the blocks, however. Although six-inch blocks can be purchased, in my opinion that is just too much stress on the springs and leaves. In short, I recommend getting the full leaf-pack if you can afford it. You will end up with a better ride, less to worry about and higher quality springs than the stock units. However, if lift blocks are the way you wish to go, be careful and remember not to overdo anything. What is OK on the street may be very dangerous off-road, and vise-versa. Play safe and have fun!