2011-2016 Ford F-350 Super Duty Leaf Springs: Decoding Spring Codes for the Right Fit
This guide covers how to find the correct rear leaf springs for your Super Duty using the door sticker code, inspect a used set, and diagnose common failures like sagging and noise.
- The spring code on your driver's door jamb sticker ('SPR') is the ONLY way to guarantee you get the correct replacement leaf spring.
- Always replace leaf springs in pairs to maintain a level ride height and ensure safe, predictable handling.
- When buying used, inspect for cracks near the center pin and mounting eyes, and avoid springs with heavy, flaking rust.
- Single Rear Wheel (SRW), Dual Rear Wheel (DRW), and Chassis Cab models use different, non-interchangeable springs.
The Most Important Step: Find Your Rear Spring Code
Before you buy a replacement leaf spring, you must identify your truck's specific spring code. Using the wrong spring can result in an unlevel truck, poor handling, and incorrect load capacity. The only way to guarantee a match is by checking the Safety Compliance Certification Label on your driver's side door jamb.
How to find your code: Open the driver's door and locate the large sticker on the door pillar. Look for the letters 'SPR' near the bottom. There will be a two-letter code. The second letter in this code identifies your rear springs. For example, if the code is 'VB', your rear spring code is 'B'. You must match this code when buying a replacement.
Common Spring Configurations & Warnings
The 2011-2016 F-350 was available in many configurations, and the leaf springs are not interchangeable between them. The spring code on your door sticker is the final word, but here are some general guidelines and warnings to be aware of:
- Single Rear Wheel (SRW) vs. Dual Rear Wheel (DRW): These models use different leaf springs. A DRW (dually) spring is typically designed for a higher payload and will not fit or function correctly on an SRW truck, and vice-versa.
- Pickup vs. Chassis Cab: Chassis Cab models, which are sold as an incomplete vehicle to be upfitted with a service body or flatbed, have a different frame width and use different springs than standard pickup models.
- With or Without Auxiliary Spring: Many F-350s are equipped with a top-mounted auxiliary leaf spring (also called a helper or overload spring). This smaller spring only engages when the truck is heavily loaded to provide extra support. If your truck has one, your replacement spring assembly must also have one. If it doesn't, the replacement should not have one.
Warning: The initial data provided mentions several spring codes (D, F, G, H, L, M, P). For example, 'D' is often for DRW models, while 'L' or 'M' might be for SRW models with an auxiliary spring. However, without an official Ford decoder for this specific generation, you should not rely on generalized lists. Always match the code from your door sticker to the code of the part you are buying.
Symptoms of Failing Leaf Springs
1. Vehicle Sagging or Leaning
The most common symptom of a worn-out leaf spring is a noticeable sag in the rear of the truck. If the truck leans to one side, it indicates the spring on that side has failed or is significantly weaker than the other. This happens as the steel leaves lose their arch and strength over time and miles, a process called fatigue.
2. Clunking, Rattling, or Squeaking Noises
As springs wear, the pads between the leaves can degrade, causing the steel leaves to slap against each other, resulting in a clunking or rattling noise over bumps. A persistent squeak or groan, especially under load or during suspension movement, can be caused by rust and friction between the leaves or at the shackle bushings. On trucks with overload springs, a common source of clunking is the overload leaf hitting its frame-mounted strike plate.
3. Visibly Broken or Cracked Leaf
A sudden drop on one side of the truck, often accompanied by a loud bang, can mean a leaf has cracked or broken completely. This is a critical failure. Sometimes a smaller leaf in the pack can break and even fall out without the driver noticing immediately, leading to a gradual sag. Visual inspection is key to finding these breaks.
Buying a Used Leaf Spring: What to Inspect
A high-quality used OEM leaf spring can be an excellent value, often outlasting a cheap new aftermarket part due to superior materials and engineering. However, a thorough inspection is critical before purchasing.
- Check for Cracks: This is the most important check. Carefully inspect each leaf, paying close attention to the area around the center pin/bolt and the 'eyes' at each end where the spring mounts. A line of rust running across a leaf can hide a crack.
- Assess Rust Condition: Surface rust is normal and acceptable. However, avoid any spring with deep, flaking, or pitted rust, as this weakens the steel and can lead to failure.
- Look for Deformation: Lay the spring on a flat surface. It should have a consistent arch. Avoid any spring that is bent, twisted, or looks flat (has lost its arch). A flat spring is a worn-out spring.
- Inspect Bushings and Pads: Check the rubber or polyurethane bushings in the eyes of the spring. They should be intact, not cracked, rotted, or pushed out. Also, check the small pads between the individual leaves. If they are missing or crumbling, the spring will be noisy.
- Verify the Spring Pack: Count the number of leaves and check for the presence of an overload spring. Ensure it matches the original spring from your truck exactly.
Known Issues, TSBs, and Recalls
As of this writing, there are no specific NHTSA recalls or Technical Service Bulletins (TSBs) for rear leaf spring failure on the 2011-2016 Ford F-350 Super Duty. However, owners on forums frequently report two main issues:
- Broken Leaves: Individual leaves, including the main leaf, can break due to metal fatigue, impact from hitting a large pothole (especially in cold weather), or overloading. This is not considered a manufacturing defect but rather a potential failure point on any high-mileage, hard-working truck.
- Overload Spring Noise: On models equipped with overload springs, a loud clunking noise is common when driving over bumps unloaded. This is caused by the end of the overload spring making contact with its strike pad on the frame. Some owners add thicker pads or apply grease to quiet this down.
Replacement Overview & Difficulty
Replacing the rear leaf springs on an F-350 is a physically demanding job that requires heavy-duty tools and strict adherence to safety procedures.
- Difficulty: 4 out of 5
- Time: 2-4 hours per side, more if dealing with heavy rust.
- Process: The basic process involves safely lifting the truck and supporting the frame on high-capacity jack stands, supporting the rear axle with a floor jack, removing the wheel, removing the U-bolts that hold the spring to the axle, and unbolting the spring from its front hanger and rear shackle. Installation is the reverse of removal.
Warning: Leaf springs are extremely heavy and under tension. The truck must be supported correctly on the frame, not the axle. Always use new U-bolts when installing leaf springs, as the old ones stretch and are not safe to reuse. Bolts may be seized with rust and require heat from a torch to remove.
Cost Comparison
Prices can vary significantly based on supplier and location. These are estimates to help understand the value of different options.
| Part Source | Estimated Price (Per Spring) |
|---|---|
| New OEM | $650 - $1,100 |
| New Aftermarket | $250 - $500 |
| Used OEM | $150 - $350 |
| Shop Labor | $400 - $800 (for a pair) |
Frequently Asked Questions (FAQ)
Do I have to replace leaf springs in pairs?
Yes, you should always replace leaf springs in pairs. Replacing only one will result in an uneven ride height, with the truck leaning to one side. It will also cause unpredictable handling and braking characteristics as the suspension will be stiffer on one side than the other.
Can I upgrade my F-350's leaf springs for more capacity?
Yes, aftermarket companies offer heavy-duty (HD) leaf spring packs and add-a-leaf kits to increase payload capacity or provide lift. However, be aware that increasing spring stiffness will result in a harsher ride when the truck is unloaded. It is also important to note that adding heavier springs does not legally increase your vehicle's Gross Vehicle Weight Rating (GVWR).
What causes my leaf springs to squeak and how can I fix it?
Squeaking is usually caused by friction between the individual leaves due to dirt, rust, or worn-out insulator pads. A temporary fix is to spray a dry lubricant (like graphite spray) between the leaves. Avoid using wet grease, as it attracts and holds dirt, which can accelerate wear. The long-term solution is to replace the springs or have them disassembled, cleaned, and reassembled with new pads.
What are the torque specs for the U-bolts?
Torque specifications are critical for safety. While they can vary slightly, a common torque spec for the 2011-2016 F-350 U-bolts is around 185 lb-ft. However, you should always verify with a model-year-specific service manual for the exact procedure and specification. U-bolts should be tightened in an even, crisscross pattern.
Technical Specifications
OEM Part Numbers: AG138A080AD AG138A080SA BC34-5560-D BC3Z-5560-B BC3Z-5560-C BC3Z-5560-D BC3Z-5560-L BC3Z5560B BC3Z5560C BC3Z5560D BC3Z5560E BC3Z5560F BC3Z5560G BC3Z5560H BC3Z5560L
Specifications like leaf count, arch, and length vary by spring code. The primary identifier is the spring code on the vehicle's Safety Compliance Certification Label.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Ford F-350 Super Duty:
- 🛍️ Shop This Part
- The Most Important Step: Find Your Rear Spring Code
- Common Spring Configurations & Warnings
- Symptoms of Failing Leaf Springs
- 1. Vehicle Sagging or Leaning
- 2. Clunking, Rattling, or Squeaking Noises
- 3. Visibly Broken or Cracked Leaf
- Buying a Used Leaf Spring: What to Inspect
- Known Issues, TSBs, and Recalls
- Replacement Overview & Difficulty
- Cost Comparison
- Frequently Asked Questions (FAQ)
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