How do I Determine what Flex Air Pinbox Fits My 2018 Grand Designs Solitude Trailer?

Updated 04/20/2022 | Published 04/19/2022

Products Featured in This Question

Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000 lbs

(199)

$1678.44

Trailair Flex Air 5th Wheel Pin Box - Lippert 0719 - 18,000 lbs

(2)

$1492.72

Question:

I have 2018 grand designs solitude 310gk And looking to up grade the pin box to the flex air, which model should I order?

asked by: William B

Expert Reply:

On your 2018 Grand Design Solitude 310GK, there are a couple factors that influence what Flex Air model you need. First off, you need to account for the weight. From my research, that model has a gross vehicle weight rating of 15,000 pounds and a hitch weight rating of 2,350 pounds. The second thing you need to know is what model of pinbox you currently have installed on the trailer. If you do not know what pinbox model you currently have, I went ahead and attached diagrams of the measurements of common pinbox models for you to compare to yours.

Once you identify your pinbox, the correct model of Flex Air needs to be compatible with your pinbox as well as your weight capacity needs. For instance, if you have the Lippert 1621 pinbox, you need the Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000 lbs # LC328492. As another example, if you have the Lippert 0719 pinbox, you need the Trailair Flex Air 5th Wheel Pin Box - Lippert 0719 - 18,000 lbs # LC328484.

It is important to note that you cannot use these models if you have any type of gooseneck adapter installed.

expert reply by: Bob C