Comparing the 18K and 21K Lippert 1621 Flex Air 5th Wheel Pin Boxes

Updated 08/04/2020 | Published 05/11/2019

Products Featured in This Question

Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 21,000 lbs

(199)

$1830.34

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

(199)

$1661.53

Question:

What is the difference between 18000lbs And the 21000lbs flex air pin boxes Please give the details

asked by: Rudy M

Helpful Expert Reply:

The Trailair Flex Air 5th Wheel Pin Box part # LC369535 which is rated for 21,000 lbs is constructed of a thicker metal and also has beefier welds when compared to the Trailair Flex Air 5th Wheel Pin Box part # LC328492 which is rated for 18,000 lbs. The air bag and shock that is used in each of them are the same. The thicker metal and welds are what gives the former a higher weight capacity. The best option for you would be the one that meets the GVWR of your trailer though you could go higher for more of a safety margin if you wish to.

expert reply by: Conner L

Mike W.

7/27/2020

I am looking at the air ride pin box and I have the LIPP 1621 HD. My camper gvwr is 18,000 lbs. What is the difference between the Air Ride, the Trail Aut and the Flex Air that you carry

Jon G.

8/4/2020

What pin box part numbers are you looking at? The difference between the Air Ride and Flex Air pin boxes is that the Flex Air has a pivoting plate to help battle chucking while the Air Ride only has the shock and air bag (just like the Flex Air). Here is a link to our selection of pin boxes that replace the 1621HD like what you have.

Helpful Links

dept-pg-fifth_wheel_king_pin-co-1621hd.aspx