Replacing the springs on a tandem axle trailer is a challenging but achievable task for mechanically inclined individuals, significantly improving ride quality and safety. The process involves supporting the trailer safely, disconnecting and removing the old springs, installing new ones, and ensuring everything is torqued to specification, ultimately restoring the trailer’s suspension and load-bearing capacity.
Why Replace Your Tandem Axle Trailer Springs?
Tandem axle trailer springs are the unsung heroes of hauling. They absorb road shock, distribute weight, and ensure your trailer tracks smoothly. Over time, however, these springs can weaken, crack, or break due to constant stress, corrosion, and heavy loads. Ignoring worn-out springs can lead to:
- Reduced towing stability: A bouncy or unstable trailer is dangerous and can make hauling a nightmare.
- Uneven tire wear: Worn springs can cause the trailer axles to shift, leading to premature tire wear.
- Damage to trailer components: Excessive vibration and jarring can damage other parts of the trailer, such as the frame, wiring, and cargo.
- Increased risk of accidents: Spring failure while towing can be catastrophic.
Replacing your tandem axle trailer springs is essential for maintaining safety, performance, and the longevity of your trailer. Let’s delve into the process step by step.
Preparing for the Replacement
Gathering Your Tools and Materials
Safety is paramount, so gather the following tools and materials before starting:
- New tandem axle springs: Ensure they match the existing springs in terms of length, width, capacity, and number of leaves. Know your Gross Axle Weight Rating (GAWR).
- Jack and jack stands: Heavy-duty jack and stands rated for the trailer’s weight are crucial.
- Wheel chocks: Essential for preventing the trailer from rolling.
- Sockets and wrenches: A comprehensive set in both metric and imperial sizes.
- Torque wrench: To tighten nuts and bolts to the correct specifications.
- Penetrating oil: To loosen rusted bolts and nuts.
- Hammer: For tapping out stubborn bolts.
- Pry bar: For leverage and aligning components.
- Grease gun: For lubricating spring bolts and bushings.
- Safety glasses: To protect your eyes from debris.
- Gloves: To protect your hands.
- Work light: To illuminate the work area.
- Measuring tape: For verifying spring dimensions.
- Camera or phone: To take pictures for reference during disassembly.
Ensuring Trailer Safety
- Park on a level surface: A flat, stable surface is essential for safe jacking.
- Chock the wheels: Place wheel chocks behind and in front of the wheels on the axle not being worked on.
- Disconnect the trailer: Unhitch the trailer from the tow vehicle and disconnect the electrical wiring.
Removing the Old Springs
Lifting and Supporting the Trailer
- Position the jack: Place the jack under the trailer frame, as close as possible to the axle being worked on. Refer to your trailer’s manual for recommended jacking points.
- Raise the trailer: Slowly and steadily raise the trailer until the tires are off the ground.
- Position jack stands: Place heavy-duty jack stands under the trailer frame, ensuring they are securely positioned.
- Lower the trailer onto the jack stands: Carefully lower the trailer onto the jack stands, ensuring they are supporting the weight. Never work under a trailer supported only by a jack.
- Remove the wheels: Once the trailer is securely supported, remove the wheels on the axle you’re working on.
Disconnecting the Springs
- Spray with penetrating oil: Liberally apply penetrating oil to all bolts and nuts connecting the springs to the axle and frame. Let it soak for at least 15-30 minutes.
- Remove the U-bolts: These secure the axle to the spring. Loosen and remove the U-bolts, keeping track of any shims or spacers. Note the orientation for reassembly.
- Remove the spring bolts: These connect the spring eyes (the loops at the ends of the spring) to the hangers on the frame. These bolts can be very stubborn due to rust and corrosion. Use a hammer and punch to help drive them out if needed.
- Remove the springs: Once all bolts are removed, the spring should be free to remove. If it’s stuck, use a pry bar to gently separate it from the hangers.
Installing the New Springs
Preparing the New Springs
- Grease the spring bolts: Apply grease to the threads of the new spring bolts and the inside of the bushings in the spring eyes.
- Inspect the hangers: Check the hangers on the trailer frame for any damage or wear. Replace them if necessary.
Installing the Springs
- Position the spring: Align the spring eyes with the hangers on the frame.
- Install the spring bolts: Insert the spring bolts through the hangers and spring eyes, tightening the nuts finger-tight.
- Position the axle: Place the axle on top of the spring, ensuring it is centered.
- Install the U-bolts: Install the U-bolts over the axle and spring, tightening the nuts finger-tight. Remember to reinstall any shims or spacers in their original positions.
- Torque to specifications: Using a torque wrench, tighten all bolts and nuts to the manufacturer’s specified torque settings. This is crucial for ensuring proper suspension function and preventing loosening. Consult your trailer’s manual or a reliable online resource for torque specifications.
- Repeat for the other side: Repeat the process for the other spring on the same axle.
Final Steps
- Reinstall the wheels: Reinstall the wheels and tighten the lug nuts to the correct torque specifications.
- Lower the trailer: Carefully lower the trailer from the jack stands.
- Remove the jack stands: Remove the jack stands.
- Torque lug nuts again: Double-check the lug nut torque after driving a short distance (e.g., 50 miles).
- Test drive: Take the trailer for a test drive to ensure the suspension is working properly and there are no unusual noises or vibrations.
Frequently Asked Questions (FAQs)
Q1: How do I determine the correct spring capacity for my trailer?
To determine the correct spring capacity, you need to know the Gross Axle Weight Rating (GAWR) for each axle on your trailer. This information can usually be found on a sticker or plate on the trailer frame. Divide the GAWR by two to get the required spring capacity per spring. Always err on the side of a slightly higher capacity spring if you are unsure.
Q2: What is the difference between leaf springs and torsion axles?
Leaf springs are a traditional suspension system consisting of curved steel plates stacked together, providing load support and flexibility. Torsion axles, on the other hand, use a rubber cord or bar inside a metal tube that twists to provide suspension. Leaf springs are generally more durable and easier to repair, while torsion axles offer a smoother ride and require less maintenance, but can be more expensive to replace.
Q3: Should I replace both springs on an axle at the same time, even if only one is broken?
Yes, it is highly recommended to replace both springs on an axle at the same time. Replacing only one spring can result in uneven weight distribution and handling problems, as the old spring will likely be weaker than the new one.
Q4: What are the signs that my trailer springs need to be replaced?
Signs that your trailer springs need replacing include: visible cracks or breaks in the spring leaves, excessive sagging, bottoming out frequently, uneven tire wear, and a bouncy or unstable ride.
Q5: Can I upgrade to heavier-duty springs on my trailer?
Yes, you can upgrade to heavier-duty springs, but it is essential to ensure that the rest of your trailer components, such as the frame, axles, and tires, are also rated for the increased load capacity. Consult with a trailer specialist to ensure compatibility and safety.
Q6: What is a spring equalizer, and why is it important?
A spring equalizer is a device that connects the springs on a tandem or triple axle trailer, distributing weight evenly between the axles. It allows the axles to articulate independently, improving ride quality and reducing stress on the springs and frame. A properly functioning equalizer is crucial for tandem axle trailer performance.
Q7: How often should I inspect my trailer springs?
You should inspect your trailer springs regularly, ideally before each trip, and especially after hauling heavy loads or traveling on rough roads. Look for any signs of damage, wear, or corrosion.
Q8: What type of grease should I use for lubricating spring bolts and bushings?
Use a high-quality, water-resistant grease specifically designed for automotive suspension components. Lithium-based greases are generally a good choice.
Q9: Are there any special tools required for replacing tandem axle trailer springs?
While most of the tools required are common, a torque wrench is essential for tightening bolts to the correct specifications. A ball joint separator (pickle fork) can also be helpful for separating stubborn spring components, but is not always necessary.
Q10: Can I weld repairs to my trailer springs?
Welding repairs to trailer springs is generally not recommended. Welding can weaken the spring steel and create a potential point of failure. It’s always best to replace damaged springs with new ones.
Q11: What are the different types of leaf springs available for trailers?
Common types of leaf springs include:
- Slipper Springs: Have a curved end that slides along a hanger or bracket.
- Double-Eye Springs: Have an eye (loop) at both ends for connection to hangers.
- Eye-to-Slipper Springs: Have an eye at one end and a slipper end at the other.
Choose the spring type that matches your trailer’s original configuration.
Q12: What are the legal considerations for replacing trailer springs?
Ensure that any replacement springs meet or exceed the original specifications for your trailer’s GAWR to remain compliant with safety regulations. Consult local laws regarding trailer modifications if you are unsure. It is always recommended to keep records of all maintenance and repairs performed on your trailer.
By following these steps and taking the necessary precautions, you can successfully replace your tandem axle trailer springs and ensure a safe and enjoyable towing experience. Remember, if you are uncomfortable with any part of this process, it is always best to consult with a qualified trailer mechanic.