Over the years I have purchased my fair share of trailers – a couple new and many more used. There many things I feel that I know a lot about, because I have made a few bad purchases, but I also have made a bunch of good ones.

As the boating season is coming to an end, some boaters may be looking to find a trailer to store the boat for the winter. If you’re looking to buy a used boat trailer now or planning on buying a boat that comes with a used trailer, bring a measuring tape.

With older trailers, the capacity plate or sticker may be long gone or too hard to read after being outside in the weather for years. But if you’d like to know a rough idea of a spring-axle trailer’s capacity, simply measure the diameter of the axle. An outer diameter (OD) axle tube size of 1.75 inches is typically rated for about one ton; 2.375 inches for 3,500 pounds; and 3 inches for 5,200-7,000 pounds. Remember to subtract the weight of the trailer from the gross capacity.

Buying out of state can be interesting, but can be done. Don’t let a good deal just over the line in the Keystone State scare you. Trailers aren’t built the same because states? trailering regulations aren?t the same. While most states require brakes for trailers rated to carry more than 3,000 pounds., some states require brakes on trailers as light as 1,500 pounds, while a few others let you coast up to 4,500 pounds, although that’s not recommended. It can be expensive to retrofit brakes, and some states, such as Florida, require brakes on each axle. State-specific trailer registration information can be found at drivinglaws.aaa.com.

After an hour at highway speeds, a 13-inch tire will have spun 10,000 revolutions more than a 15-inch tire, which means more heat, bearing wear and increased chance of problems. Having a fully serviced spare tire ready to go and – here’s the important part – having the tools to install it, will solve many of the most common reasons for a trailer breakdown. If all else fails, having an annual BoatUS membership with Unlimited Trailer Assist roadside assistance to safely tow both your boat trailer and tow vehicle up to 100 miles will make a bad roadside breakdown suddenly get much better.

Watch out for paperwork snafus. Not having ownership documents can sink a sale faster than you can say, ”Did you put the plug in.” If the trailer is missing the vehicle identification number (VIN), it cannot be legibly read or doesn’t match ownership paperwork, you may run into an issue with the DMV and have to apply for a replacement. It’s better to have the seller handle this before the sale. This can be dealt with at the DMV in New York also.

Good luck and remember this saying: On anything used, the warranty runs out when you hook it up to your truck.