How to Properly Crank Up Front Trailer Supports After Coupling a Semi-Trailer

What is the correct way to crank up the front trailer supports (dollies) after coupling a semi-trailer?

a) Until they touch the ground.

b) Just a little bit.

c) As high as they can go.

d) It varies depending on the load.

Final Answer:

When coupling a semi-trailer, crank up the front trailer supports (dollies) as high as they can go. These supports are designed to only support the trailer's weight when not attached to a tractor. A trailer bouncing on a highway is likely empty as the lack of weight makes it more susceptible to bouncing.

After coupling a semi-trailer, you should crank up the front trailer supports (also known as dollies) as high as they can go.

The reason is these supports are designed to hold the trailer's weight when it is detached from the tractor. During transit, however, the trailer's weight should be supported fully by the tractor and wheels of the trailer itself. Having the dollies touch the ground can potentially cause damage or accidents on uneven surfaces or during maneuvers.

Regarding a bouncing trailer, if you notice that a trailer is bouncing up and down slowly on a highway, it is more likely that the trailer is nearly empty.

A heavily loaded trailer tends to have less bounce due to the weight of the load, whereas an empty or lightly loaded trailer is more prone to bouncing because of the lack of weight to absorb the shock.