Driving overweight is not allowed.
That's why weight distribution inside the trailer should be in the driver's direct interest. Otherwise, he might get a ticket.
A correct tractor-trailer weight per axle distribution prevents many operational issues. But the most important is avoiding getting a ticket from DOT officers.
But imagine that you realize that the truck is overweight somewhere in the middle of the road.
What can you do to fix the weight inside the trailer?
Find below the steps to distribute the weight inside a 53 semi-trailer.
1. Know the truck tare weight before loading
While loading, the shipper should consider the truck tare weight (the total weight of the tractor and trailer when empty).
The truck tare weight considers three factors.
The semi-tractor weight is usually between 18,000 and 21,000 lbs.
The empty semi-trailer weight is around 15,000 lbs.
While being at the shipper, the fuel tanks should be considered full.
Now, from the total legal weight of 80,000 lbs, exclude the tare weight. That way, you receive the amount of freight that can be legally loaded on the trailer.
Aim to fit the weight per axle rules. The U.S. axle load limits on tractor-trailers are:
- 12,000 lbs on the tractor steer axle.
- 34,000 lbs on the tractor drive axle.
- 34,000 lbs on the trailer axle.
At this point, there are two things to consider:
- the truck's capability to handle that much weight.
- the distribution of the freight inside the trailer.
Ideally, the freight would be distributed evenly on 800 lbs. pallets inside the trailer.
But, often, the pallet weight is not identical.
So, if irregular weights are present inside the trailer, place heavier cargo in the middle and the lighter cargo in the nose and rear.
2. Ask the shipper to remove the extra freight
If you know the truck's tare weight, then you can visually determine when the trailer is overloaded. In this case, ask the shipper to remove the cargo from the trailer.
But, if the loaded freight visually doesn’t go over the legally allowable loaded amount, it can still be overweight.
If the positioning of the load inside the trailer is wrong, then it can be overweight on a group of axles.
Once the trailer is loaded, it's on the driver to ensure that the weight is legal. He can do that by going to a truck weigh station.
3. Secure the load from the inside shifts
If the shipper loads the freight without securing it then the load might shift forward or laterally during the travel. That can affect the weight distribution inside the trailer.
When loading a trailer, make sure that the load is secured with straps, ropes, or chains to avoid weight shifts through transit.
4. Physically move the weight inside the trailer
If the trailer is loaded and you left the shipper, but the weight ticket shows that the truck is overweight, try moving the weight physically.
If the type of freight allows you to move it inside the trailer, change the weight distribution until you get the correct numbers on the weight ticket.
5. Slide the tandems of the trailer
Sliding the trailer tandems back and forward distributes the weight between the drive axles and trailer tandems.
Check out this video of "The Dillon Smith" who demonstrates how to perform this technique.
6. Slide the 5th wheel
Slide the 5th wheel to distribute the weight between the steer axle and the drive axle.
7. Burn fuel
Add or burn fuel to change the amount of weight onto the truck's steer axles or on your drive axles, depending on where the fuel tank is located.
8. How to reduce weight on the steer axle
On most tractors, you can move the position of the 5th wheel to change the distribution of weight.
Sliding the 5th wheel changes the weight distribution almost exclusively between the steer axle and the drive axles.
The trailer tandems see little or no effect from sliding the 5th wheel.
If you slide the 5th wheel toward the nose of the tractor, the weight on the steer axle increases, taking weight off the drive axles.
If you move the 5th wheel toward the rear of the tractor, you increase the weight on the drive axles decreasing the weight on the steer axle.
Every truck driver should know the above steps of distributing the weight on a tractor-trailer.