REVOLUTION Lowering Kit

Nolathane lowering kits are rear lowering blocks for leaf-sprung pickups and trucks. Lowering blocks, also called drop blocks, lower the rear of the vehicle by changing where the axle sits on the leaf spring, without changing the spring itself. They?re a straightforward way to get a lower rear stance on a street truck.

This range supplies rear lowering blocks only. It doesn?t include lowering springs, front drop parts or complete drop kits. Rear lowering blocks change more than ride height, so it?s worth understanding what they do, what else the job needs, and what trade-offs come with a lower rear. Each listing shows the drop height and fitment.

How Rear Lowering Blocks Work

On a leaf-sprung rear end, the axle is clamped to the leaf spring with U-bolts. The axle sits on a perch, and the spring?s center pin locates the axle in the right position along the spring.

A lowering block changes the axle?s position relative to the spring. Depending on the layout, the block sits between the spring and the axle perch, so the axle is held closer to the frame. The spring stays the same, so its rate and the way it absorbs bumps don?t change. Only the ride height drops.

Because the spring isn?t touched, lowering blocks are one of the simplest ways to lower a leaf-sprung rear. The job involves unclamping the axle from the spring, fitting the block, and clamping it back together with new U-bolts.

Lowering Blocks and Complete Lowering Kits

The term ?lowering kit? covers a wide range of products. A complete lowering kit for a truck may include lowering springs, front drop spindles or control arms, shorter shocks, and flip kits that move the axle to the other side of the spring for a bigger drop.

This range supplies the rear blocks. Blocks alone are enough when you want a moderate drop at the rear only, or when the front is being lowered with separate parts. For large drops, a lowering block on its own isn?t the right tool, and other parts are needed to keep enough suspension travel.

Choosing a Drop Height

Choosing a drop height is mostly about the stance you want and how much travel the suspension can give up.

Match the front. Many trucks sit with the rear higher than the front from the factory, so the rear can carry a load without sagging. A rear drop brings the rear down level with the front, or lower. If the front is also being lowered, choose a rear drop that matches the front height for a level stance.

Keep enough travel. Every inch of drop comes out of the suspension?s travel before the axle reaches the bump stop. A bigger drop leaves less room for the suspension to compress over bumps and under load.

Check bump stop clearance. Measure the gap between the axle and the bump stop before and after lowering, and make sure there?s still a usable amount of travel.

Each listing shows the drop height.

U-Bolts and Hardware

Fitting a lowering block changes the distance the U-bolts have to clamp, so the original U-bolts are usually the wrong length. Check the length needed for your setup. Always fit new U-bolts, nuts and washers. Once U-bolts have been torqued, they?ve stretched and can?t reach the same clamp load again. The Leaf Spring Bolts page covers measuring and choosing U-bolts in detail.

The block must also locate the spring?s center pin correctly. The center pin keeps the axle in the right position along the spring, and if it doesn?t seat in the block properly, the axle can shift.

Pinion Angle, Axle Wrap and Bump Stops

Lowering changes the geometry at the rear axle, and that has knock-on effects.

Pinion angle. The pinion angle is the angle of the differential?s input shaft relative to the driveshaft. Changing the ride height can change that angle. If the angles are too far out, you can get driveline vibration, especially under acceleration. Some blocks are angled to help correct this.

Axle wrap. Under hard acceleration, torque tries to twist the axle housing, which winds up the leaf spring in an S shape. Lowering blocks add distance between the spring and the axle, which can increase axle wrap. That shows up as wheel hop or a shudder when launching hard.

Bump stops. With less travel available, the axle reaches the bump stops sooner. Without enough clearance, the suspension can bottom out harshly over bumps.

After fitting, check for driveline vibration on a test drive, and check that the suspension isn?t bottoming out over bumps.

Load, Towing and Ride

A lowered rear has less travel available before the axle reaches the bump stop. That doesn?t change the vehicle?s rated capacities on paper, but in practice there?s less room for the suspension to compress under load.

Carrying heavy loads or towing with a lowered rear needs extra care. The rear can sag onto the bump stops sooner, and a loaded trailer adds weight at the hitch. Stay within the vehicle?s rated payload and towing capacities, and consider how you use the truck before choosing a drop height.

Fitting Lowering Blocks

• Support the frame and axle safely, so the axle can be lowered away from the spring under control
• Work on one side at a time, so the axle stays located
• Fit the block with the spring?s center pin located correctly
• Fit new U-bolts, nuts and washers
• Torque the nuts in a cross pattern to specification
• Re-torque after the first few miles, because the parts settle as they bed in
• Check bump stop contact, the driveshaft, and the slack in the brake lines, so nothing is stretched at full droop
• Have a wheel alignment done if needed, and check the headlight aim

U-bolts and axle hardware are safety-critical, so qualified fitting is recommended.

Limitations and Trade-Offs

• There?s less suspension travel and less practical load capacity
• Ride can be harsher over bumps
• Axle wrap and pinion angle can change
• Blocks lower the rear only
• Very tall blocks are generally discouraged, for stability reasons

Compliance and Insurance

Lowering rules, minimum ride height and headlight aim requirements vary by state, so follow the inspection requirements of the state where your vehicle is registered. Tell your insurance company about any modifications.

Warranty and Support

Nolathane lowering blocks are backed by Nolathane?s warranty. If you need help choosing a drop height, our local support team can help.

Shop Lowering Kits

Lowering blocks are listed in our universal auto parts selection.

Find the right rear lowering blocks for your pickup, and order online with fast shipping. Every block is covered by our fitment guarantee, and easy returns apply if anything isn?t right.