Reese Goose Box 5th Wheel To Gooseneck Adapter For a 2021.5 Forest River 377FL

Question:

Do you know what model number goosebox fits the frame on a 2021.5 Forest River Sabre 37FLL? I cant seem to figure out where to find what frame I have on this fifth wheel no matter where I search. Thanks for any help!

asked by: Devon M

Expert Reply:

From the images that I can find on your 2021.5 Forest River Sabre 377FLL it appears that it uses the Lippert 1621 pin box. The Reese Goose Box 5th-Wheel-to-Gooseneck Adapter # RP85FR is the correct replacement for the Lippert 1621 pin box. You can verify that is what you have by the sticker on the pin box itself. If you cannot locate the sticker you can verify the measurements on the bolt holes for the pin box.

The 1621 uses a horizontal bolt spacing of 7-7/8" on center and a vertical spacing of 2". The bolt holes are 5/8" in diameter.

A Tow Ready Safety Chain Kit # 49150 is required since you are moving to a ball connection.

I have included a link to our article on pin box identification below in case you find you have something different.

expert reply by: Bud M