Drivers

Tech Tip: Fifth Wheel Coupling and Uncoupling Procedures

November 2013, TruckingInfo.com - WebXclusive

by SAF-Holland

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This Tech Tip is the first in a series to be issued by SAF-Holland. The following steps are recommended by SAF-Holland for coupling and uncoupling your fifth wheel. However, we recommend that you follow your specific fifth wheel manufacturer’s instructions.

Coupling Preparation

1. Prior to coupling, you MUST inspect the fifth wheel and mounting. Perform and verify the following:

  • Tighten loose fasteners.
  • Replace missing fasteners.
  • Repair/replace missing, cracked, or otherwise damaged components.
  • Clean grease grooves if a large amount of debris is present.
  • Lubricate fifth wheel-to-trailer contact surfaces, if needed.
  • Inspect fifth wheel mechanism. Lubricate dry or rusty components.
  • If it’s a sliding fifth wheel, make sure both plungers are fully engaged.
  • Inspect air line connections.
  • Make sure fifth wheel is in appropriate position for weight distribution on the tractor. For proper positioning of the wheel, refer to manufacturer’s instructions.

2. Make sure coupling area is flat, level, and clear of persons and obstacles.

3. Tilt ramps of fifth wheel downward.

4. Make sure locks are open. If locks are closed:

a. Manual Release: If equipped with a manual secondary lock, first pull secondary release handle and hook on casting. Pull the release handle completely out.
b. Air Release: Set the tractor parking brake and pull the fifth wheel release valve until locking mechanism opens and locks in place. Release the pull valve. Release the tractor parking brake.

5. Visually inspect fifth wheel throat to ensure locks are completely open and ready to accept kingpin.

6. If locks are not completely open, check the following:

a. Specifically for the Holland FW35 Model – Shaft adjustment nut and washer are away from front of wheel.
b. Release handle is in extended “open” position.

7. If both of these conditions exist, the fifth wheel will still be able to be coupled even though the lock jaws appear closed. The movement of the kingpin into the fifth wheel jaws will allow them to open and successfully couple.

If either above conditions do not exist, repeats Steps 4 – 6.
 
Coupling
1. Chock trailer wheels.

2. Position the tractor so the center of the fifth wheel is aligned with the kingpin.

3. Traveling in a straight line, slowly back tractor to trailer. STOP the tractor before making contact with the trailer.

4. Set tractor parking brake and place into neutral.

5. Completely exhaust air from tractor suspension, ensuring that the fifth wheel is below the contact surface of trailer.

6. Exit the cab and make sure the fifth wheel is below the upper coupler plate. Verify proper fifth wheel height. If trailer is too low, use landing gear to raise the trailer height.

NOTE: For proper operation of landing gear, follow the landing gear manufacturer’s instructions.

7. Slowly back up, using lowest gear possible. Stop when fifth wheel is under the leading edge of the trailer.

8. Set tractor parking brake. Place in neutral. Exit cab and verify proper fifth wheel to kingpin alignment.

9. Adjust tractor suspension to ride height. The fifth wheel plate face MUST make contact with the upper coupler plate and raise the trailer. If fifth wheel does not make contact with the upper coupler plate, use the landing gear to lower the trailer until fifth wheel makes contact.

IMPORTANT: If trailer is too high, the kingpin will not properly connect with the lock jaw.
WARNING: Failure to couple with the trailer at the proper height could result in improper coupling, allowing tractor and trailer separation, which if not avoided, could result in death or serious injury.
IMPORTANT: Never inflate the tractor suspension when the kingpin is above the throat of the fifth wheel.
CAUTION: Failure to avoid inflating tractor suspension when the fifth wheel is not forward of the king pin, could result in damage to the kingpin and fifth wheel.

10. Slowly back into the trailer, engaging kingpin in the fifth wheel.

11. Connect the air and electrical lines.

12. Raise the landing gear legs until the pads are just above the ground.

13. Perform a pull test as an initial check by locking the trailer brakes and pulling forward with the tractor to make sure that tractor-trailer separation does not occur.

14. Set the tractor parking brake.

15. Exit the cab and visually inspect for the following to ensure that the lock is closed.

a. Nut and washer must be snug against the fifth wheel casting.
b. No gap is permissible between the trailer upper coupler plate and the fifth wheel.
c. Fifth wheel locks must be closed around the trailer kingpin with 1/4 inch
(6.35 mm) or less gap visible between the lock jaws.

16. If you do not achieve a proper couple, repeat the coupling procedure. Refer to the fifth wheel manufacturer’s instructions.

WARNING: Failure to properly couple the tractor and trailer could result in tractor-trailer separation while in use which, if not avoided, could result in death or serious injury.
IMPORTANT: DO NOT use any fifth wheel that fails to operate properly.
WARNING: Failure to repair a malfunctioning fifth wheel before use could result in tractor-trailer separation which, if not avoided, could result in death or serious injury.

17. Fully retract the landing gear legs off the ground and secure the crank handle.

NOTE: For proper operation of landing gear, follow the landing gear manufacturer’s instructions.

18. Remove the wheel chocks and continue with the pre-trip inspection.

NOTE: For no-tilt fifth wheels used with rigid upper couplers, always remove no-tilt shaft assembly for on-road use.
 
Uncoupling Procedures

1. Position the tractor and trailer, in straight alignment, on firm, level ground clear of obstacles and persons.

2. Set the trailer brakes.

3. Slowly back the tractor tightly against the trailer to relieve pressure on the fifth wheel locks.

4. Set the tractor parking brake.

IMPORTANT: DO NOT exhaust air from tractor suspension before uncoupling.
WARNING: Failure to avoid exhausting tractor suspension before uncoupling could result in difficulty uncoupling tractor from trailer which, if not avoided, could result in damage to the fifth wheel and kingpin.

5. Chock the trailer wheels.
6. Lower the landing gear until the pads just touch the ground.

NOTE: For proper operation and ability to transfer trailer weight from the fifth wheel, follow the landing gear manufacturer’s instructions. DO NOT raise trailer off of the fifth wheel.

7. Disconnect the air and electrical lines from the trailer and secure to tractor.

8. If equipped, pull the secondary lock release handle and hook on casting.

9. Pull the release handle. If air release equipped, pull and hold the fifth wheel release valve until locking mechanism opens and locks in place.

10. Specifically for the Holland FW35 Model – Ensure locking mechanism is open and yoke shaft is in out position with handle out.

11. Release the tractor parking brake and slowly pull forward 12 to 18 inches (306 – 457 mm) to disengage kingpin from fifth wheel. Fifth wheel should be between the front edge of trailer and kingpin.

IMPORTANT: DO NOT drive the tractor free of the trailer.

12. Set the tractor parking brake and place into neutral. Completely exhaust air from tractor suspension, ensuring that the fifth wheel is below the contact surface of trailer.

13. Visually inspect uncoupling. Make sure the trailer is completely supported by the landing gear.

14. Release the tractor parking brake and slowly pull away from the trailer.

15. Apply air to the tractor air suspension and allow suspension to return to ride height.
 

Comments

  1. 1. Harold Jones [ November 08, 2013 @ 05:14AM ]

    In a perfect world surfaces are all level and every driver would be anxious to study and follow the long procedure you outlined. Personally, I think you lost most people very early in your dissertation. I would suggest that an effective presentation should be limited to 5 or 6 key focus areas. Areas like; Check to ensure the 5th wheel is free of ice, snow, excessive grease or any other debris. Ensure the mechanism is in good working order and properly adjusted. (I don't know anyone who will stop and exit the cab as many times during the process as you suggest)

    In 22 + yearss of fleet management I have seen several accidental disconnects. The majority were either caused by the trailer being too high causing the kingpin to sit on top of the jaws or in cold weather, drivers pulling forward too quickly after contacting the kingpin. The locking mechanism needs a little extra time to work in very cold conditions. The primary cause of trailers being dropped on their nose was, in my experience, caused by drivers failing to roll the gear down before pulling out from under the trailer.

    In driver training I have found K.I.S.S. to be the most effective training presentation.

  2. 2. J.Chalk [ December 01, 2013 @ 06:21AM ]

    Thank you Mr.Jones!

 

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