TransAm Truck preparing to couple with a trailer

Coupling: Step 1 – Locking the 5th Wheel around the Kingpin

By TransAm Trucking / January 3, 2017

Coupling is when the truck’s 5th wheel locking jaws lock around the trailer’s kingpin. This connection allows the truck to haul the trailer. Proper coupling techniques can prevent unnecessary damage to the equipment.

Grease 5th Wheel

Example of a greased fifth wheel.Before doing anything else, make sure your 5th wheel is properly greased. A properly greased 5th wheel prevents unnecessary wear to your tires and other damage to the equipment. Grease in and around the grooves on the 5th wheel. Once this is complete, you are ready to continue.

Properly Aligned

Before backing into a trailer, approach the trailer from the driver’s side.When starting your coupling maneuvers, approach the trailer from the driver’s side. This gives you the greatest visibility during the maneuver. Once you are in front of the trailer, make sure you are directly in line with the trailer. You want to back in straight. Backing under the trailer at an angle can cause damage the equipment. When the rear drive axle is under the trailer, stop the truck, get out and look. You are verifying 3 things: alignment, the 5th wheel’s position, and clearance.

Look at the ground. Make sure the trailer and the truck are on a level surface. Look for potholes or dips under the tires. If the ground under the truck or trailer is not level, you run the risk of damaging the equipment if you continue to back up.

Your 5th wheel needs to be aligned with the kingpin and not in an elevated position.Look at the 5th wheel. Your 5th wheel needs to be aligned with the kingpin and not in an elevated position. If the 5th wheel is propped up, you could damage it and the trailer if you continue to back up.

Verify the clearance. Make sure the trailer is at the proper clearance for the 5th wheel to back under the trailer. Remember to stay safe. Do not crawl under the trailer to check these items. If all these things are good, return to your truck to continue your coupling maneuver.

Tug Test

Once the 5th wheel locks around the kingpin, perform a tug-test. Release the tractor brakes, leave the trailer brakes engaged, and place the truck in drive. Slowly drive forward just enough to feel resistance on the 5th wheel. This ensures the trailer is indeed connected.

The 5th wheel release arm must be in to ensure the coupling is successful.

After the tug test is complete, it’s time to hook up the electrical line and air lines to the trailer…

Make it a safe day!

*Safety tips brought to you by Thomas Young and the Training and Development Department of TransAm Trucking