Rusted Leaf Springs

By Dianne Catapang Written by Dianne Catapang
Updated on May 6, 2023

Leaf springs are a vital part of your boat trailer’s suspension system. They support the entire weight of the trailer and the boat combined. So, you must always check if they are in good condition.

Leaf Springs are your boat trailer’s weak spots. Most trailers are made of metals that do not rust, but the leaf springs do. Neglect this, and you would not be able to use your trailer.

Rusted Leaf Springs

You use trailers to launch your boat. When doing so, it gets submerged into water. As you probably already know, some metals corrode – they rust when exposed to water and oxygen. And leaf springs are made of those metals. 

Without proper care, you may encounter problems. For example, you may not be able to launch or retrieve your boat using your trailer. You may not even be able to transport it in the first place.

So, taking proper care of your trailer’s leaf springs is necessary. Here’s what you need to know about this matter. 

Can leaf springs rust?

Leaf springs are very reliable because they are incredibly strong and resilient. However, they are made from non-galvanized steel that is susceptible to rust.

Now, boat trailers frequently get exposed to water since you use it to launch and retrieve your boat. And water is one of the factors that cause rusting.

That said, you indeed need preventive maintenance to ensure your trailer does its job. 

Well maintained set of trailer leaf springs can last over 15 years. In contrast, a poorly-maintained set will need replacing after just a few years.

Rusted Leaf Springs

Should I replace rusty leaf springs?

You don’t necessarily need to replace rusty leaf springs. Not because they are no longer shiny means you need to throw them in the scrapyard.

Here’s how you determine if you need to replace them.

If the lower leaves of your boat trailer spring touch each other, they are still okay. You don’t have to buy a replacement set yet. Also, you may be able to salvage it through restoration.

On the other hand, if there are spaces between the ends of the lower leaves, it is time to get a new set.

How do you restore rusty leaf springs?

If you can save your trailer’s leaf springs, do so. It will save you money. Here’s how you can restore them.

Step 1: Prepare for disassembly.

Rusted Leaf Springs

The first step is to take the leaf springs apart. This way, you will have access to spots otherwise inaccessible when you try to clean the leaf springs as a whole.

Remember to mark where the center pin is. You should measure the distance between the center point and the springs’ two ends. It ensures that your leaf springs will line up perfectly when you reassemble them.

Step 2. Disassemble the leaf springs

Rusted Leaf Springs

Before taking out the center pin, use a C-clamp on the leaf springs. The springs are under pressure, so removing the pin will cause them to fly everywhere. With a C-clamp, they will stay together, and you can slowly loosen the clamp up so they will not fly away.

Step 3. Clean the leaf springs

Rusted Leaf Springs

Use a wire brush on an angle grinder to clean the springs. Remember to wear a respirator because you would not want to breathe in the nasty particles you will remove from the springs.

Step 4. Treat the leaf springs with rust dissolver

Rusted Leaf Springs

Paint the springs with a rust dissolver to ensure that there will be zero rust left after restoration. Paint both sides plus the edges of the springs with the dissolver. Then, leave them overnight.

Clean the leaf springs with acetone, then hand them up. Then, start painting. Use a primer before coating the leaf springs with paint. 

Step 5. Reassemble the leaf springs and put them back to the trailer

Clean the leaf springs with acetone, then hand them up. Then, start painting. Use a primer before coating the leaf springs with paint. 

Put everything back together. Make sure you check the notes you made earlier to ensure the leaf springs line up properly.

How much does it cost to rebuild leaf springs?

Rebuilding or replacing leaf springs can cost anywhere from $450 to $790. 

Parts are priced between $504 and $533, while labor is estimated at between $164 and $207. And installation alone could range from $95 to $170 – which depends on where you go.

What happens if a leaf spring breaks?

Leaf springs breaking causes detrimental effects. It would result in significant damage to your trailer and boat. That may include complete suspension failure, cracks in the frame, tire or hub damage, and trailer axle damage.

Can I replace just one leaf spring?

When one leaf spring breaks, it may be an indication that the other leaf spring is worn-out, cracked, or fatigued too. So, while you can technically replace just one leaf spring, it would be best to replace them both.

How do you know if you need new leaf springs?

If the leaf springs are badly rusted, it would be best to replace them rather than try to restore them.

Also, try looking through your leaf springs during the day. If there are gaps and you can see through, a replacement is in order. Having gaps is a signal of fatigued leaf springs due to age or excess weight.

And speaking of age, if your leaf springs are at least 14 years old, it is highly recommended that you replace them.