The position of the axles on a trailer is key to properly balancing the load. This balance is important to maintain the correct downward force at the tongue. A specific amount of weight on the trailer's tongue helps to maintain the connection to the vehicle's hitch. Too much weight and you will lift the front of the vehicle, reducing braking and cornering ability. The ideal tongue weight is 10-15% of the trailer's total mass. You can determine this weight with a tongue scale.
Measure the length of the trailer's cargo box with the measuring tape. This measurement doesn't include the trail tongue.
Calculate the center point of the two axles by multiplying the trailer's length by 0.6. The center of the two wheels will be 60 percent of the trailer's length.
Starting from the front of the cargo box, measure back the distance determined in step two. Mark this location with the chalk. Repeat this step and mark the other side of the trailer.
Mount the tandem trailer's equalizer hangers on both sides in the marked location. This will act as the center of both axles. Mount the axles to this hanger.