What To Know When You Call For Help
Measure your trailer from the end of the tongue to the end of sterndrive or outboard. The easy way to do this is to run the tape measure under the entire rig, or in sections if your rig is longer than 25 feet.
You probably know this one, but if the dispatcher needs to hunt down replacement parts to get you moving again, they will ask.
Boat Height On Trailer
Measure from the ground to the highest fixed point on the boat.
Measure the overall width of the boat and trailer at its widest point. This may be at the trailer's fenders, or if the boat has significant flare, it could be the boat itself.
Tire Size & Bolt Pattern
In the dark or driving rain, it's hard to read the tire size off the sidewall. Jot it down now. It should be a combination of letters and numbers such as "ST225/75R 15" or similar.
"ST" stands for Special Trailer, the only type of tires recommended for use on trailers due to their stiffer sidewall construction. The first and largest number is the width of the tire in millimeters, the second number is the ratio of the height of the sidewall to the width of the tire. The letter that follows indicates that the tire is either (R) radial, or (B) bias ply, and the final number is the diameter of the wheel.
The bolt pattern refers to the number of lug nuts it takes to keep the wheel in place. Larger trailers may have six-bolt patterns as opposed to five.
Boat & Trailer Weight
If you've never weighed your rig fully loaded, a visit to a truck stop scale is in order. While you're at it, check your tongue weight, too. To find out how, see "Tongue Weight DIY".
— Published: Spring 2014
Every trailer owner needs to know the weight of the trailer tongue on the hitch
While bearing problems are second for calls to TRAILER ASSIST, tire trouble remains at the top
A flat tire on a boat trailer should be regarded as serious as a tire failure on the tow vehicle and addressed immediately