Why is the Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000 lbs Not 12" Wide

Question

Question:

Hello, I received my new Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000. My original Lippert 1621 HD is 12in wide exactly. this new one is 11.75 wide. is this normal? Do I need to add some washer to go to 12in?

asked by: Alain

1

Helpful Expert Reply:

The Curt Flex Air 5th Wheel Pin Box part # LC328492 is 11-7/8" wide per Curt. The pin box brackets on the trailer should have an inside to inside width of 12". This leaves about a 1/16" gap on either side which is completely normal. If they made the pin box any wider you'd run into tolerances issues between the brackets and pin box. There won't be a gap between the pin box and bracelets once the hardware is torqued.

expert reply by: Conner L

1

Answer 1

Since you are concerned about dips, RRs, and bumps in curves, I recommend using a shock absorber like #LC283271 or #LC281281 on your 5th wheel trailer. You stated the mounting hardware is already in place, so adding shock absorbers should be easy and…

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Answer 2

The 1621 and 1621HD OEM pin box both have the same bolt pattern, so since your 5th wheel will max out at 14K, you can certainly use the 18K Trail Air Flex Air, part #LC328492. According to Lippert, when the Trail Air Flex Air is fully inflated, the…

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Answer 3

Trailair Flex Air 5th Wheel Pin Box #LC328492 has the same width as the pin box it is meant to replace (Lippert 1621 pin box) which is 12 inches wide (outer width). I have linked a video covering the features of this pin box for you.

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Answer 4

Great question, Jeff! When the Rota-Flex first came out it renovated what a pin box could do and be, but at this point in time that technology is a little more dated and the Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box #325-GH-8040 is the "new…

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Answer 5

I spoke with my contact at Trailair and from your serial number we were able to determine that your trailer came with a 1621 HD pin box which is a long pin box style. I was unable to obtain the exact part number for your Trailair pin box but from the…

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Answer 6

There should be a sticker or plate on the pin box itself that lists the manufacturer and model of the pin box. If it is not present then there are some measurements you can take to determine the model of the pin box. I have included a link that…

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Answer 7

Because it's lighter, less expensive, has fewer moving parts and is mechanically less complicated I'd recommend going with the Gen-Y #325-GH-8040 shock absorbing pin box versus a Trailair Flex Air like part #LC328492. The Trailair features a…

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Answer 8

If you're getting that much bounce out of your trailer that would lead me to believe that maybe the MORryde IS suspension system is the actual issue. Typically if the suspension is too stiff you'll start to bounce. We see this issue a lot…

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Answer 9

Trailair Flex Air 5th Wheel Pin Boxes, such as the Lippert #LC328492, are designed to replace the existing pin box on your trailer. The long and short jaw models that you referenced in your question simply refer to the type of pin box that the unit…

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Answer 10

Even though you weren't able to find a sticker or label on your pin box to determine the make and model number, I have a solution to be able to determine which pin box is on your 2011 Dutchman Voltage 3900. Selecting the style pin box and then…

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Answer 11

I checked with the manufacturer for you, and the 12V, 10.7 Cu Ft Everchill RV Refrigerator w/ Freezer #EV77FR needs 160 Watts and two group 27 batteries for constant use. Keep in mind that power is only for the fridge though and not all your other…

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Why is the Curt Flex Air 5th Wheel Pin Box - Lippert 1621 - 18,000 lbs Not 12" Wide

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