Sliding the tandem axle group along a trailer to adjust the weight distribution on each axle group is a common practice for most truck drivers.
Knowing how to slide tandems on a semi-trailer and how to do it safely is an essential part of a truck driver’s job.
Why truck drivers should know how to slide tandems
There are a few reasons why most truck drivers should know how to properly slide the tandems on a semi-trailer:
- To ensure the overall weight of their tractor-trailer is distributed in the best way possible.
- To meet the legal requirements of the states in which they drive.
- To comply with regulations governing how far back or forward trailer tandems can be moved (also known as the distance between the kingpin on the trailer and the trailer’s tandem axle group).
How to distribute weight on a tractor-trailer
It is important for truck drivers to understand the positions of the axles on a tractor-trailer. Axles are a contributing factor to whether a driver hauls a load safely and legally.
Most tandem axles can be moved forward and backward along the length of the trailer to ensure proper weight distribution on the tractor and trailer axles.
Many semi-trailers have sliding tandem axles that are mounted directly on the frame rails under the trailer. When the weight of a load being hauled is unbalanced, a driver has two options:
- Transfer weight to the tractor by sliding the axles of the trailer back.
- Transfer weight to the trailer by sliding the axles of the trailer forward.
Each tandem hole accounts for approximately 250 pounds of weight transfer, which means:
- If you move the tandems back by one hole, you transfer 250 pounds to the tractor axles.
- If you move the tandems forward by one hole, you add 250 pounds to the trailer.