Park the tow vehicle and trailer in a straight line on a smooth, flat surface (a large parking lot is ideal). Disconnect the trailer and drive the tow vehicle free of the trailer tongue.
Adjust the trailer with the tongue jack so it appears to sit level. With the tape, measure the distance from the ground to the bottom frame of the trailer, front and rear. The measurements should be equal. If not, adjust the tongue jack up or down until the measurements are equal. Record these measurements for future reference.
Measure the distance, on the tow vehicle, from the ground (bottom of the tire) to the highest point of the outside edge of the fender wells, rear and front. Record these measurements.
Measure the distance from the top inside of the hitch coupler on the trailer to the ground. (This is the part that fits down over the hitch ball on tow vehicle.) Record this measurement.
Measure the distance from the ground to the top of the hitch ball on the tow vehicle. Record this measurement . With the tongue jack, raise the trailer coupler about 1 inch higher than this ball measurement.
Back the tow vehicle to the trailer. With the tongue jack, lower the trailer coupler to the hitch ball, then attach and lock the coupler.
Retract the tongue jack so the full weight of the trailer rests on the tow vehicle hitch. Measure the ground-to-wheel well distance on both axles of the tow vehicle. Record this measurement.
Adjust the hitch if the measurement of the tow vehicle's rear height has increased, and the measurement of the vehicle's front has decreased. There is too much weight being transferred to the front, and you must redistribute it by lowering the L-brackets or removing several spacer washers from the angle set bolt.
Adjust the hitch if the measurement of the tow vehicle's rear height has decreased by more than 1.5 inches, and the measurement of the vehicle's front has increased, because not enough of the load is placed on the vehicle's front axles. Raise the L-brackets or add spacer washers to the angle set bolt.
If the rear measurement of the tow vehicle is the same or only slightly lower (1 to 1.5 inches) and the front measurement is the same or only slightly higher, the hitch is in good adjustment.
Measure the trailer heights again. Compare these measurements with the previous numbers. A difference of 1.25 inches or less is OK, but if there is a higher measurement in the front, move the hitch head down one hole on the shank. A lower measurement on the front means you need to move the hitch head up one position. Drive the vehicle and trailer a short distance. If it handles well, all is OK.
