Why Leaf Springs are a Great Sprinter Suspension Upgrade

With all the weight of an interior build and exterior gear, many adventure vans operate near or at their maximum GVWR. This puts immense wear on the suspension of the vehicle, especially while off-roading.

Stock Sprinter van suspension isn’t meant to support everything we put in our vans, and it certainly isn't meant to be mobbed down back roads to that campsite you scoped out. Investing in an upgraded spring pack can dramatically improve the handling of your vehicle and improve the suspension system’s longevity.

Here, we’re going to take a deep dive into leaf springs, break down some of their innovative features, and answer all of your top questions about upgrading your van’s suspension.

What is a Leaf Spring?

Leaf springs are the stacked, thin pieces of metal located behind your van’s rear wheels under the wheel well. They serve three main purposes:

1. Improve Ride Quality: Driver and passenger comfort is the primary purpose of leaf springs. They absorb road vibration and reduce any movement caused by potholes, rocks, and uneven road conditions.

2. Support Vehicle Weight: Springs support most of the weight that’s over the rear axle and distribute it throughout the vehicle.

3. Elevate the Vehicle Body: Leaf springs keep the body level over the chassis and prevent sag.

What are the Parts of a Leaf Spring?

Leaves

The different lengths of stacked metal are called the leaves, and they are responsible for the bulk of the support. The heavier-duty the vehicle is, the more leaves it will have in its stack. The leaf spring clamp and bolts securely hold this stack together in the middle.

Eye

On each end of the leaf stack is an eye. This is where the ends of the leaves are rolled to reduce vibration. The main eye is the larger of the two, and it’s attached directly to the vehicle. The smaller one is attached to a shackle.

Leaf Spring Bushings

Bushings sit in the center of each eye. They are a rubber component that helps reduce vibrations.

Leaf Spring Shackle

Shackles act as a pivot point between the smaller leaf spring eye and the frame. It allows the leaves to compress and release while going down the road.

The Limitations of Stock Mercedes Sprinter Leaf Springs

Out of the gate, Sprinter van parts are not designed to handle the demands of off-road adventure. GVWR limits for 2025 Sprinters range from 9,000-12,000 pounds and it’s easy to hit this once you start adding bicycles, cargo boxes, battery systems, and more. Ford Transit van suspension has even lower ratings.

Despite their versatility, Sprinters are originally intended to be used for transportation and delivery. Engineers do not put thought into designing the suspension system for off-road use or full-time living. Due to this, it’s crucial that upgrades are made before these vans are taken out on any trail or excursion.

Video: Stock Mercedes Sprinter Leaf Springs on the Trail

John from Owl saw firsthand just how poorly equipped the stock Mercedes Sprinter leaf springs are for the weight of a build. In this video, you can see that the bump stops are fully compressed, which can cause a van’s rear wheels to get airborne as it goes over bumpy terrain.

Complete Sprinter Van Suspension Upgrades vs. Leaf Springs

Many customers at Owl find themselves stuck between investing in a complete suspension upgrade or just a standalone leaf pack. Each has its own use cases, and it’s not always necessary to invest in a complete suspension overhaul.

An upgraded leaf pack only comes with the leaves, bushings, and clamp. It’s a plug-and-play installation and improves load handling and riding comfort. They come in at about half the price of a complete suspension system. For an even more budget-friendly option, you can consider an add-a-leaf.

Complete suspension systems have all the bells and whistles. In addition to new leaf springs, they feature new front and rear shocks, bump buddies, and all of the necessary hardware. A sprinter suspension upgrade also gives you the opportunity to invest in a Sprinter lift kit.

Sprinter Van Suspension Kit	New Leaf Springs
Includes leaf springs, front and rear shocks, bump buddies, and hardware. Improves all aspects of suspension - handling, driving, passenger comfort, and safety. Double the price of leaf springs alone. Can be bundled with a lift kit.	Includes upgraded leaf springs, clamps, and bushings. Improves rear-end sag and weight distribution. Good suspension upgrade for people on a budget. Easier installation.

The Innovation of Deaver Leaf Springs

A quality leaf spring pack is crucial to meet the suspension demands of a fully-loaded van. Owl has partnered with Deaver to offer custom leaf packs using progressive, high-carbon steel.

Jeff Crosby and Scott Born of Deaver Suspension were interviewed by MotorTrend and explained the following:

“High leaf counts of thinner material using quality high-carbon rate steel allow you to utilize that thinner material without compromise of sag or fatigue. In the simplest of terms, take 10 pieces of notebook paper and see how they can flex and move compared to four pieces of cardboard. The staggered leaf lengths allow us to get a much more progressive spring rate that increases as each leaf is engaged. This allows a smoother cycling of the suspension that doesn’t get the bucking reaction or rebounding.”

Stronger Suspension Means Better Adventures

Stock Sprinter suspension wasn’t engineered for the demands of off-road travel and the added weight of aftermarket gear. Once a van is fully built out, the factory leaf springs often bottom out, causing poor handling, uneven ride height, and long-term wear on key components. Upgraded leaf springs offer the support that stock setups lack.

Owl partners directly with Deaver to offer custom-engineered leaf springs tailored for real-world van use. If your suspension is showing signs of strain, explore our field-tested solutions and enjoy smoother journeys wherever you take your rig.

Frequently Asked Questions

What Do Leaf Springs Do?

Leaf springs support the weight of your Sprinter van, maintain ride height, and control rear axle movement, which are crucial for handling, especially under load or uneven terrain.

How Should Leaf Springs Look?

Properly functioning leaf springs should have a smooth arc and sit evenly side to side; visible sagging, flattening, or rust separation between leaves is a sign they need replacement.

Do I Need a Leaf Spring Upgrade When Installing a Sprinter Van Suspension Lift?

If you're lifting the rear or adding weight (like gear, cabinets, or overlanding equipment), upgraded leaf springs are necessary to maintain correct geometry, stability, and ride quality.