Vertical Measurement from Bottom of Gooseneck Coupler to Lowest Bolt Hole on 20k Reese Goose Box

Updated 05/03/2024 | Published 02/09/2018

Question:

I see a couple of answers to questions regarding vertical measurements reference the bottom of the ball pocket. I dont see any vertical measurements to the center of the ball. Can you give me the vertical distance from the bottom of the ball pocket to the center of the ball, or better yet, the vertical distance from the center of the ball up to the lowest set of holes on the wing mounts? If I had that measurement I can determine the vertical distance from the top of the bed rails to the underside of the 5th wheel. I want to be sure I will have enough room to get a bed cover I want to order.

asked by: Don T

Expert Reply:

I reached out to my contact at Reese, and the Goose Box 5th-Wheel-to-Gooseneck Air Ride Coupler Adapter 20K # RP85FR has a vertical measurement of 19.2 inches from the bottom of the ball connection to the lowest bolt on the pin box. You will want to measure your pin box as well to determine the clearance to that same bolt.

You will want to make sure you have 5-6 inches of clearance from the top of your bed rails to the underside of your 5th wheel for turning clearance on hills. If you'd like a recommendation for your tonneau cover, let me know the year/make/model of your truck and bed size.

expert reply by: Jason S

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Christopher J.

3/31/2024

2022 F350 7.3 liter gas 4.3 rear end short bed thinks it’s like 6.75 foot or 6.825. I ordered the Reesebox 20K Gen3…. will it fit and what offset ball would work?

Mike L.

5/3/2024

@ChristopherJ The Goose Box units are pin box specific, so you'll want to make sure you order the proper Goose Box for your pin box model or the bolt holes will not line up. If you could reply and tell me which model OEM pin box you have, I can recommend the correct Goose Box model for your setup. The longest offset ball we offer for the Ford tow/prep package is the # GY43XR which has a 5 inch offset. The concern here is that unless your 5th wheel RV has the concave front corners and the RV manufacturer has specifically stated that the 5th wheel will work on short bed trucks, you likely won't have enough clearance for turns. There is a handy formula you can use to determine if you will have the necessary cab clearance to make a 90 degree turn with your short bed truck and a Reese Goose Box like # RP85FR. The formula is as follows: (A + B) - C = Clearance A = Distance from center of gooseneck ball to truck cab B = Length of Offset C = Width of trailer divided by 2 (this comes out to 48" for your trailer). In order to ensure cab clearance during 90 degree turns this clearance number needs to be at least 4.