1. Fifth Wheel King Pin
  2. Gen-Y Hitch
  3. 1621
  4. 1621HD
  5. Lippert
  6. Reduces Bounce and Jarring
Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box - Lippert 1621 and Lippert 1621 HD - 18,000 lbs

Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box - Lippert 1621 and Lippert 1621 HD - 18,000 lbs

Item # 325-GH-8040
lowest price pledge
Our Price: $1,318.82
You Save: $81.17
Fifth Wheel King Pin
This item qualifies for Free Shipping
Shipping Weight: 126 lbs
In Stock
325-GH-8040 - Lippert Gen-Y Hitch Fifth Wheel King Pin
zoom in icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

This shock-absorbing pin box provides a smooth, safe ride while you tow your fifth-wheel trailer. The all-in-1 box is virtually maintenance-free - no air bags to refill or small parts to replace. The weight scale lets you monitor your vertical load. Call 800-298-8924 to order Gen-Y Hitch fifth wheel king pin part number 325-GH-8040 or order online at etrailer.com. Free expert support on all Gen-Y Hitch products. Guaranteed Lowest Price and Fastest Shipping for Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box - Lippert 1621 and Lippert 1621 HD - 18,000 lbs. Fifth Wheel King Pin reviews from real customers.
  • All Info
  • Q & A (3)
  • Videos (1)
  • Photos
  • Why etrailer?

Gen-Y Hitch Fifth Wheel King Pin - 325-GH-8040

  • 1621
  • 1621HD
  • Lippert
  • Reduces Bounce and Jarring
  • Gen-Y Hitch
  • 18000 lbs GTW
  • Pin Box Replacement
  • Fixed Turret

This shock-absorbing pin box provides a smooth, safe ride while you tow your fifth-wheel trailer. The all-in-1 box is virtually maintenance-free - no air bags to refill or small parts to replace. The weight scale lets you monitor your vertical load.


  • 5th-Wheel king pin box upgrades the existing pin box on your 5th-wheel trailer
    • King pin inserts into your truck's 5th-wheel hitch
  • Shock-absorbing design ensures a smooth, steady ride
    • Technology functions like a torsion axle to limit transfer of road shock from trailer to truck and vice versa
      • Reduces chucking and rough fore-and-aft motion
      • Limits bounce and jarring up-and-down motion
    • No airbags to maintain and fewer moving parts to repair or replace than with other shock-absorbing solutions
  • Pin weight scale is built in to help you balance your trailer
    • Meter lets you know if your load needs to be adjusted before you tow
  • Heavy-duty steel construction
  • Powder coat finish resists wear and corrosion
  • Simple, bolt-on installation
    • Mounts with existing bolts
  • Made in the USA


  • Designed to replace Lippert 1621 and 1621 HD 5th-wheel pin boxes
  • Towing capacity: 18,000 lbs
  • Pin weight capacity: 3,500 lbs
  • 5-Year limited warranty

Built-In Shock Absorption for a Smooth Ride

Executive torsion

If you've ever towed a fifth-wheel trailer before, you're no stranger to road shock. Driving over uneven terrain can result in a rigid, bumpy ride. And uncomfortable fore-and-aft chucking can occur when you're starting and stopping. When all of the motions combine, the road shock can even potentially damage your truck or trailer.

This Gen-Y Hitch torsion pin box is designed to absorb road shock at the connection point to create a safe, smooth ride. This is thanks to the internal construction of the box, which is similar to that of a torsion axle.

Pivot points are built into the Gen-Y pin box. This allows for movement between the box, which attaches to your trailer, and the king pin, which connects to the fifth-wheel hitch in your truck bed. When your trailer bounces or jerks, the king pin will move accordingly.

torsion diagram

Built into the Gen-Y pin box are tubes with inner bars that are surrounded by rubber cords. As the king pin moves, these inner bars twist inside of the tubes, attempting to follow the pin's motion. But the rubber cords prevent the bars from twisting too far. And as each bar turns, these cords compress to absorb the rough shock. This means that any shock experienced by your truck can be absorbed before it reaches your trailer, and the shock experienced by your trailer won't get transferred to your truck.

Easily Check Your Vertical Load

Executive scale

The vertical load, or pin weight, refers to the weight that a fully loaded trailer exerts downward on the hitch in the truck bed. Too little vertical load can cause trailer sway and too much can cause poor performance.

This Gen-Y pin box has a built-in mechanical scale so that you can check to see if your vertical load is too high or too low. The highest arrow on the scale indicates your maximum vertical load (3,500 lbs). The lowest arrow indicates no vertical load (0 lbs). A vertical load of at least 2,000 lbs is recommended for the built-in shock absorption to function effectively. This means that the scale's white indicator marker should be between the highest arrow and the middle arrow when you hook up your trailer to tow.

GH-8040 GenY Hitch Executive Fifth Wheel King Pin Box with Torsion Shock Absorption - Lippert 1621 and Lippert 1621 HD - 18K

Video of Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box - Lippert 1621 and Lippert 1621 HD - 18,000 lbs

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of Gen-Y Hitch Fifth Wheel King Pin - Pin Box Replacement - 325-GH-8040


Ask the Experts about this Gen-Y Hitch Fifth Wheel King Pin

  • Will the Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box Cause the Trailer To Be Nose High
    The Gen-Y Hitch Shock Absorbing 5th Wheel Pin Box part # 325-GH-8040 will have dimensions similar to the Lippert Trailair RotoFlex so you should not have an issue with the trailer not being level if you did not before. That said, I have attached a photo with the dimensions of the pin box for you if you want to confirm beforehand. If the trailer was nose high after installing the pin box and making your adjustments, there is always the option to raise the trailer like with the Dexter...
    view full answer...
  • Does Gen-Y Hitch 325-GH-8040 Replacement Pin Box Have a Minimum Tongue Weight it Will Work With
    The Gen-Y Shock Absorbing Pin Box, part # 325-GH-8040 has a shipping weight of 126 lbs. Once the shipping packaging is removed, it'll weigh about 115 lbs. According to Gen-Y, the replacement pin box will work great for a 1625 lb fifth wheel pin weight, there isn't a minimum tongue weight. I've linked you to a product description video that you might find helpful.
    view full answer...
  • Recommended Cushioned Replacement for Lippert 1116 OEM Pin Box
    The Gen-Y # 325-GH-8040 Replacement Pin box is only compatible with the Lippert 1621 and 1621 HD pin boxes. I'd recommend going with the Trailair Air Ride Pin Box, part # LC155943. This pin box uses both an air bag and a shock absorber to mitigate the chucking, banging and rattling caused by excessive up and down and side to side movement of the pin box in the 5th wheel hitch making for a more comfortable (not to mention peaceful) ride. Gen Y doesn't offer the 325-GH-8040 in a version...
    view full answer...

Do you have a question about this Fifth Wheel King Pin?

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality fifth wheel king pin for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate fifth wheel king pin information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Expert Research:
Mike L
Edited by:
Lindsey S
Written by:
Alexander C
Installed by:
Michael B

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.