How To Adjust A Fontaine No Slack Fifth Wheel

The Fontaine No Slack fifth wheel plays a vital role in the functionality of numerous heavy-duty trucks, facilitating the secure and effective hauling of trailers. However, to maintain its peak functionality, it is necessary to conduct regular upkeep and fine-tuning. This piece will explore the process of adjusting a Fontaine No Slack fifth wheel.

Step 1: Inspect the Fifth Wheel

Before making any adjustments, it is important to inspect the fifth wheel for any signs of wear or damage. Look for any cracks, rust, or other visible defects that may affect its performance. If you notice any issues, address them before proceeding with the adjustment process.

Step 2: Check the Kingpin

The kingpin is a crucial component of the fifth wheel, as it connects the trailer to the truck. Make sure that the kingpin is properly lubricated and free from any debris or damage. If necessary, clean and lubricate the kingpin to ensure smooth operation.

Step 3: Adjust the Height

The height of the fifth wheel can affect its performance and the overall stability of the trailer. To adjust the height, locate the adjustment mechanism on the fifth wheel. This may be a crank or a lever, depending on the model. Turn the mechanism to raise or lower the fifth wheel until it is at the desired height.

Step 4: Check the Locking Mechanism

The locking mechanism of the fifth wheel is responsible for securing the trailer in place. Make sure that the locking mechanism is functioning properly and that it engages securely with the kingpin. If necessary, adjust the locking mechanism to ensure a tight and secure connection.

Step 5: Test the Adjustments

After making any adjustments, it is important to test the fifth wheel to ensure that it is functioning properly. Connect the trailer to the truck and engage the locking mechanism. Check for any signs of movement or instability while driving. If everything seems stable, your adjustments are complete.


Adjusting a Fontaine No Slack fifth wheel requires careful inspection, maintenance, and testing. By following these steps, you can ensure that your fifth wheel is functioning properly and providing safe and efficient towing of trailers.