Know how to slide your tandems

Which way to slide your tandems?

A common task for truck drivers is to slide the tandem axle group along the trailer to adjust the weight on different axle groups.  Knowing which way to move the axles can be confusing.

The tandem axle groups on most trailers can be moved forwards and backwards along the length of the trailer.  Truck drivers want to be able to put the axles where the weight is best distributed, but there are regulations that vary by state and province on how far back the trailer tandems can be moved.  This is called the trailer wheelbase or kingpin to rear axle/tandems distance and refers to the distance between the kingpin on the trailer and the axle group.

What does it matter?

Governments set rules on where to set the tandems to keep the wheelbase of the truck-trailer combination smaller.  The longer the trailer wheelbase, the less maneuverable the truck-trailer combination, and the more curbs the truck will run over.

Truck drivers want to be able to set their wheelbases where ever they want.  If there is a load that is not distributed evenly in the trailer, the truck axles can be overweight, even though the entire truck is not overweight.  In this case, the tandems should be ‘pushed forward’ so more weight would be put on the trailer axles.

Let’s see how this works in practice:

Scenario 1:

TruckandTrailerTandems_SlideForward2

Scenario 2:

Also, it is possible that there is too much weight on the trailer axles.  In this case, the axles can be moved backwards to move weight from the trailer to the truck.

TruckandTrailerTandems_SlideBackward2

Caution! – There are rules governing how far back tandems can be placed.   Click here to see what the laws are where you will be traveling.

 How far should you move the axles?

A good rule of thumb is that one hole on the trailer equals 250 – 300 lbs being moved from the truck to trailer, or vice versa.

20 thoughts on “Know how to slide your tandems”

  1. To get legal weight on my tandems I go over the 41′ kingpin law for TN. How can I fix this? My company’s truck fifth wheel doses not slide and is all the way forward.

  2. Unfortunately, the only way to fix this situation is to re-load your load to put more weight on the front of your trailer, or to remove part of your load. There is no other way around it. Hope that it worked out!

  3. I work in a warehouse. My supervisor tells all the drivers to put their tandems back before they back into the docks. That way their truck bed will be level with the dock.

  4. It is just so you don’t happen to travel through a state with a 41′ restriction and you don’t have your axles set there. Also, it is easier to turn the rig around!

  5. I am 34 160 on the second axle which way do I slide the tandems and how many hoes do I have to move it to

  6. If you are heavy on your trailer axles, slide your tandems backwards. If you are only over 160 lbs, then 1 or 2 holes should do the trick.

  7. Try dishwashing soap with water in a spray bottle. It will make them a bit easier to move, but then wash away as you go down the road so you don’t collect dirt. Don’t use anything oily that will collect dirt!

  8. All of these confusing comments.
    First of all not all trailers are the same. Let me try to simplify this because when you guys say “slide your tandems this way” people get confused thinking drive the truck that way.
    The easiest way to think about which way you need to slide the tandems is this:
    The more the back of your trailer HANGS further from the tires, the MORE WEIGHT is added to the trailer axles.
    Get it? If you slide your trailer wheels all the way to the back (like the guys at the dock tell you) then the back of the trailer is not hanging behind the wheels much. Right? The tires are basically all the way back, so theres not much hanging behind. If you slide your trailer tires as far towards the truck, you will see the trailer hanging way behind the wheels.
    The more hanging in the back, the more weight is being put on the back.

  9. Good stuff, l needed this, makes the job a little easier, especially when picking up beer loads, thxs!

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