What are Available Capacities for Lippert Rota Flex Pin Boxes to Replace 1621 Pin Box

Question:

Whats the difference the 18k vs and 21k? Is the 21k heavier or built stronger? They look exactly the same so Im not sure where the extra strength comes from. I have the 18k version and since Im pulling a trailer behind the 5th wheel, Ill be at about 18400 and may need the 21k version. What do you think?

asked by: Clarendon T

Expert Reply:

For Trailair Rota-Flex pin boxes that fit as a replacement for a Lippert 1621 we have the 21k part # LC328329 and we have the # LC328330 which it sounds like you have. I can assure they aren't both really rated for 21k and the only difference is a part number and a few stickers. While the differences are hard to see by just looking at pictures of the two the 21k version is reinforced in areas you can't see and does have a higher capacity.

If you are going to be over the 18k capacity of your current pin box, even by 400 lbs we have to recommend you upgrade.

expert reply by: Jameson C