Why Can't the Curt Rota-Flex Pin Boxes Be Used with the Curt Q-Series 5th Wheel Hitches

Question:

Why cant the curt rota flex king pin be used with a curt Q series hitch?

asked by: Derek C

Expert Reply:

Hey Derek, thanks for reaching out!

The Curt Rota-Flex pin boxes, like part # LC176440 you referenced, aren't compatible with the Curt Q-Series hitches because the pin box hitch plate moves and the Q-Series hitches use a spherical axial bearing which provides a smooth ride quality for standard pin boxes, but will work against the movement of the Rota-Flex pin boxes.

Instead of the Q-Series I recommend using the A-Sers # C16140 which is pretty similar, but it has a torsion head so it will be compatible with the Rota-flex box.

expert reply by: Jon G

Derek

4/9/2024

If I am understanding it correctly, it's not that they won't connect and work together; it is just that the purpose of the two parts contradicts each other as they both provide movement, thereby negating the benefit of each other. It's not that you couldn't safely tow with it, it's just not recommended. I am trying to figure out the best path forward as I would like to keep things as they are without having to spend money, but I don't want to compromise safety. I have a Q series hitch in my truck that worked for my previous setup. I recently purchased a new trailer, and it has the Rotoflex pin, and I don't want to have to switch if I don't have to. i obviously wouldnt go out of my way to create a none standard connection but given what i have id like to make it work if i could.

Jon G.

4/9/2024

@Derek You're almost there. Curt has told us that they won't just negate the benefit of each other but they will work against each other and can damage either the pin box/trailer and/or hitch/truck. I completely understand wanting to avoid spending money, but for the safety of you and your trailer setup you'll need to swap either the pin box or hitch.