Gen-Y Gooseneck Adapter Pin Box to Replace Lippert Rhino on a 2025 Jayco Seismic 399
Updated 09/02/2025 | Published 06/26/2025
Question:
Hello, My name is Matt, I have a 2025 jayco Seismic 399. UVW 15418 GVWR 20400 pin weight 3400lbs. I would like to convert the fifth wheel to the Gen y gooseneck. I can not figure out what pin box I have. Please look at the picture attached with the white tag from pin box. Can you please tell me what Gen Y gooseneck I need so I can order from you asap. Thank you
asked by: Matthew L
(click to enlarge)
Expert Reply:
Hey Matthew, thanks for reaching out!
What you're going to need is the Gen-Y Hitch Shock Absorbing 5th Wheel to Gooseneck Pin Box # GY45GR. I confirmed with my contact at Lippert that you have their Rhino pin box so this will be an exact matchup for you!
Are you looking to swap to the gooseneck setup for an easier time hooking the trailer up?
Product Page this Question was Asked From
Gen-Y Hitch Shock Absorbing 5th Wheel to Gooseneck Pin Box - Lippert Rhino - 30K GTW - 6.5K TW
- 5th Wheel Gooseneck Adapter
- Adapts Trailer
- 5th Wheel Trailer to Gooseneck Hitch
- No Extra Clearance
- 25000 lbs
- Replaces Pin Box
- Shock Absorbing
- Lippert Rhino
- Gen-Y Hitch
more information >
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Jon G.
9/2/2025
Hey Matthew, Did you go ahead with the Gen-Y gooseneck conversion for your Jayco? I'm curious to know if it made hooking up your trailer easier. Your experience could really help others considering a similar upgrade!