With the tongue of the trailer on the scale, the load can be moved forward or backward until the proper percentage of tongue weight is obtained. Obviously, you don't need to do this every time you load your trailer. After the first time, you can come pretty close to estimating the proper tongue weight.
Don't overload your trailer! I used to own a tandem-axle utility trailer that had an 8x12-foot foot bed with 3-foot-high sides. I got a great deal on two cords of oak firewood. This wasn't the first time I'd hauled two cords of wood in the trailer, which had a 10,000-pound coupler and 3,500-pound-rated axles. The tires were rated at 2,200 pounds each. However, unbeknownst to me at the time, the weight of two cords of previously hauled dry pine was under 5,000 pounds, while the weight of this green oak was over 5,500 pounds per cord, for a load in the neighborhood of well over 11,000 pounds, plus the trailer weight. I was only a mere 4,000 pounds overweight! The outcome was a broken spindle on a busy freeway at rush hour, blocking all four lanes. Luckily, I hit no one and no one hit me.
Wiring: Anybody who has ever pulled a trailer has experienced wiring and light problems. The lights always seemed to work the last time you used the trailer-why don't they now? Suffice it to say that good, clean, tight connections are very important, as well as a very positive ground. Don't rely on the trailer ball for a ground. Use a separate grounding wire between the tow vehicle and the trailer, incorporated within the wiring plug. The first thing to check when lights don't work is the ground. Color coding the wiring can solve a lot of problems in the long run. SAE Standard J1239 calls for the following: white - ground; brown - tail and marker; yellow - left turn and stop; green - right turn and stop; blue - electric brakes; and orange - battery charge.
What About a Spare Tire? Nothing can more easily ruin a trip than having a flat tire on the trailer. If you don't want your cargo disappearing, you generally have to leave someone with the trailer as you drive to have the tire repaired or replaced.
Trailer wheels come in as many patterns as there are vehicles. The three most common are Ford passenger cars with five lugs on a 41/2-inch bolt circle, which is referred to as a "5 on 41/2"; Chevrolet wheels are 6 on 51/2; and the Jeep-Ford truck pattern is 5 on 51/2. To determine the bolt circle with an even number of bolts, measure from the middle of two holes directly across from each other. On a five-bolt pattern, measure from the back of a hole to the center of the second hole. If you're building a trailer, try to match up the bolt pattern with that of the tow vehicle. In most cases, an existing hub can be swapped for one of a different pattern.
Wheel Alignment: It's just as important on a trailer as it is on an automobile. Misalignment can cause unequal load distribution, handling problems, and excessive tire wear. Measurements should be taken from the center of the coupler back to each side of the axle ends. If they're not equal on both sides, it's time to find out why. The problem could be a bent axle, broken spring, improperly located spring hanger, or even a bent frame or tongue assembly.
Just for fun, to give you some idea of what things weigh that you may carry, here are the approximate weights of some common materials:
| Water |
8.3 lb/gal |
| Sand |
100 lb/cu ft or |
|
2,700 lb/cu yd |
| Concrete |
140 to 150 lb/cu ft |
| Cement |
94 lb/bag |
| Brick |
6 lb |
| Concrete block |
22 to 44 lb |
| Wood, green live oak |
6,500 lb/cord |
| Wood, dry pine |
2,300 lb/cord |