Trailer Spring Info

My boat trailer leaf springs are rusty, does that mean it's time for me to replace them?

Not necessarily, your trailer springs should be replaced when the lower leaves start to separate at the ends. Think about it like this: Let's say you have a four leaf spring. Put your hand up, palm facing you, with all four fingers (each one of your fingers represents a leaf of your spring) touching each other. If the lower leaves of your trailer spring look like this, then they are most likely good. Now spread your fingers apart, if the springs on your trailer have space between them (at the ends of the lower leaves) then it's time to get some new trailer springs.

How can I keep my boat trailer leaf springs from getting rusty?

I don't think that's possible. But that shouldn't stop you from trying! Coating them with an automotive rubberized under coating, or even covering them with wheel bearing grease can help for a while, but the rust will always win. A great option for "standard" width aluminum I-beam trailers (72" or 80" outside frame width) would be to get rid of the leaf springs and bolt on some galvanized torsion axles. If you need to replace the axles, leaf springs, spring hangers, shackle plates and all the mounting hardware. Then we strongly recommend going with torsion axles. In a situation where everything needs replaced, when everything is said and done, the boat trailer torsion axles can save you hundreds of dollars on the initial install. Not only that, but there is substantially less maintenance required over the torsion axles lifetime compared to leaf springs. The trailer will have a lower center of gravity, by around two inches. That translates to: The trailer will be safer to tow and you won't have to back your vehicle quite as far down the boat ramp to launch and load your boat. The ride quality will be very smooth and quiet, and you can expect to get ten years or more of service from a torsion axle. Regular boat trailer leaf springs last two or three years on average. **Remember, when upgrading to torsion axles from leaf springs, plan on raising your boat trailer fenders up a few inches to give your trailer tires the clearance they need. (Now that your trailer is riding a few inches lower) We allow 3-1/2" to 4" of clearance between the tire and your fenders under static (trailer jacked up with no weight on the axles) conditions.

How do I know which trailer springs I need to get?

The next section below shows you how to determine what type of leaf spring you have, and how to measure each different type.