bing tracking image
Q & A Icon

Can I Switch to the Reese GooseBox 20k on my Grand Design 399th 5th Wheel ?


I am trying to identify if the 20k version of the Goose Box would work on the Grand Design Momentum 399th. Any assistance you can offer in confirming that for me would be greatly appreciated!


Expert Reply:

I'm not able to say with certainty without knowing exactly which pin box your Grand Design Momentum 399th has, however, what I was able to find is that a lot of the Grand Design 5th Wheels use the same couple of pin boxes. If you can confirm that your Momentum 399th has the 1621 or 1621HD (which seem to be the most popular models), the # RP94720 would be an excellent choice. If that is not the model pin box you have on your 5th wheel, please let me know the correct model number and I will recommend a Goosebox that will work with your frame.

You can determine which pin box you have 2 ways:

1) Locate the manufacturer's name and model number located somewhere on your 5th wheel trailer's pin box. There should be a sticker or plate on it somewhere with this information and this is going to be the easiest way to determine which pin box will fit your 5th wheel.

2) You'll need to select the pin box style by comparing them to the picture attached and then take some measurements. I've attached a how-to article to this answer as well that explains in detail how to take these measurements and match them up.

expert reply by:

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>