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  1. 5th Wheel Pin Box
  2. Lippert
  3. Fabex 750
  4. Fabex 765
  5. Fabex 770
  6. RBW 7028
Trailair Air Ride 5th Wheel King Pin - Fabex 750, 765 and 770, RBW 7028 - 21,000 lbs
Lippert

Trailair Air Ride 5th Wheel King Pin - Fabex 750, 765 and 770, RBW 7028 - 21,000 lbs

Part Number: UF35-946212
In Stock
$1,773.06
5th Wheel Pin Box
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Experience smooth, stable towing with your fifth-wheel trailer by replacing your ordinary pin box with an air-ride-equipped model. The scissoring action of the coupler allows the interior air bag to absorb road shock so that you won't feel it. 1-800-940-8924 to order Lippert 5th wheel pin box part number UF35-946212 or order online at etrailer.com. Free expert support on all Lippert products. Great prices and Fastest Shipping for Trailair Air Ride 5th Wheel King Pin - Fabex 750, 765 and 770, RBW 7028 - 21,000 lbs. 5th Wheel Pin Box reviews from real customers.
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  • Reviews (79)
  • Q & A (0)
  • Photos

Lippert 5th Wheel Pin Box - UF35-946212

  • Fabex 750
  • Fabex 765
  • Fabex 770
  • RBW 7028
  • Upgraded Pin Box
  • Absorbs Road Shock and Reduces Chucking
  • Lippert
  • 21000 lbs GTW
  • Fixed Turret

Experience smooth, stable towing with your fifth-wheel trailer by replacing your ordinary pin box with an air-ride-equipped model. The scissoring action of the coupler allows the interior air bag to absorb road shock so that you won't feel it.


Features:

  • Air ride pin box replaces standard pin box on your 5th-wheel trailer to enhance performance
    • Cushions and absorbs road shock
    • Improves handling and overall ride
    • Limits strain on truck and trailer frames
  • Scissor action allows pin box to compress, compensating for jarring and bounce
    • Internal air bag absorbs the road shock
    • Built-in spring ensures that pin box rebounds - keeps air bag from breaking down
  • Direct replacement for OEM pin box
  • King pin connects to any 5th-wheel trailer hitch
  • Sturdy steel construction


Specs:

  • Designed to replace the following pin boxes:
    • Fabex 750, 765 and 770
    • RBW 7028
  • Weight capacity: 21,000 lbs
  • 1-Year warranty


Notes:

  • Not for use with any type of gooseneck adapter
  • Because of the size of this item, it ships via truck freight

Eliminate the bounce from your ride with the Trailair air ride coupler. The unique scissoring action of the pin box ensures that road shock is absorbed, preventing the harsh, rigid ride that you typically encounter while towing your fifth-wheel trailer. Not only does this improve your overall towing experience, but it also helps maintain a sound, well-functioning system. Less bounce and jarring means less stress on your truck, trailer and hitch.


Trailair Air Ride Coupler

How the Trailair Air Ride Works

When you encounter uneven terrain on your trip or hit a pothole on the highway, the Trailair pin box compresses, transferring the road shock to its internal air bag. A built-in air spring ensures that this compression occurs in a controlled fashion so that the air bag doesn't burst. It also causes the pin box to appropriately rebound, positioning it so that it's ready for the next bump in the road.



155927 Lippert Components (LCI) Trail Air Kingpin Box - L04

Replaces 35-946212 UltraFab Trail Air Kingpin Box - L04






Customer Reviews

Trailair Air Ride 5th Wheel King Pin - Fabex 750, 765 and 770, RBW 7028 - 21,000 lbs - UF35-946212

Average Customer Rating:  4.7 out of 5 stars   (79 Customer Reviews)

Experience smooth, stable towing with your fifth-wheel trailer by replacing your ordinary pin box with an air-ride-equipped model. The scissoring action of the coupler allows the interior air bag to absorb road shock so that you won't feel it.

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Works perfect.



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Exactly what I ordered very happy with the product



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So far I have not had any issues.



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Best thing I ever bought for my rv



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The product was great. The service was great. The freight company left a lot to be desired.



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This really helped with the chucking I was experiencing.



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This pin box smoothes out the ride in the truck. No more chucking. No noise at all.



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There was a mix up with the order but once it got straighten out,they reshipped another one.I told them that I needed it by Friday,I don't know how but it made.it I would use this company again in the future.
Thanks



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etrailer is and excellent site to order parts for your trailer. They walked me thru the part numbers so the pin box I ordered fit. No problems with the install and I can't wait to take my first trip with the new pin box.



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Great products fit perfect



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Good packaging and received quickly.



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GREAT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



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The pin box works perfectly.



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The Trailair pin box is a great product.
I
installed it before a 700 mile trip and it does what it is intended to do. Etrailer was very helpful in selecting the correct pin box for my trailer.
Thank you.



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Camper rides much better .. good people at etrailer thanks



by:

love it worked so good, love Etrailer also great company


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Show More Reviews

See what our Experts say about this Lippert 5th Wheel Pin Box

  • Recommended Gooseneck to 5th Wheel Hitch Adapter for a 2014 Chevy Silverado 2500 with B&W Gooseneck
    We actually have quite a few products that you can use as a 5th Wheel to Gooseneck adapter, I am linking the product selection page so you can view the different options to see what you might like. Unfortunately we do not offer any replacement pin boxes that are compatible with your RBW 7028 pin box. Although we have many options, there are a few choices that are much better than other options. Since you have a short bed, the recommended 5th Wheel Hitch for you would be a sliding 5th...
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  • Adapter For MORryde Cushioned Pin Box With Fabex 750 Bolt Pattern To Use Gooseneck Hitch
    I do have a recommendation as based on your Dimensions it sounds like you have a Fabex 750 style pin box. Currently the Trailair Air Ride 5th Wheel King Pin # UF35-946212 is our only product that will bolt to this old pin box bolt pattern. To go to a gooseneck ball connection I recommend installing the 5th-Wheel-to-Gooseneck Coupler Adapter Mounting Plate # MR37ZR. This will then allow you to weld on either the Convert-A-Ball Cushioned 5th-Wheel-to-Gooseneck Adapter # CAB-C5G for long bed...
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    Image 1 for Image 2 for
  • Available Replacement Pin Box for RBW 7028 Pin Box
    The only available option we currently have to replace an RBW 7028 pin box is the Trailair Air Ride 5th Wheel King Pin - Fabex 750, 765 and 770, RBW 7028 - 21,000 lbs # UF35-946212. This is an upgraded air ride style pin box that will help provide some added cushion against road shock and help reduce chucking, so it's a nice choice to replace your old RBW 7028.
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  • How Do Trailair Air Ride 5th Wheel Pin Boxes Work
    The Trailair Air Ride 5th Wheel Pin Boxes, such as # LC155943, are a series of air ride pin boxes designed to replace standard pin boxes on your 5th-wheel trailer. This design is to provide a cushioned, air ride. This improves handling and limits the strain on your tow vehicle. The internal air bag absorbs road shock and has a scissor-like motion that allows the pin box to compress; the built-in shock ensures that the pin box rebounds. The internal air bag should be inflated after the...
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  • How to Determine Fifth Wheel Pin Box Model
    If you are unable to contact your trailer's manufacturer with your VIN to find the factory pin box model number there are some steps you can take which will allow you to determine what pin box model you have so you can purchase a new FlexAir. To do this you will need to follow the steps in the linked help article, which I will go over with you. Start by selecting your pin box style like in the accompanying photo (which you will also find in the help article). You will then need to use...
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    Image 1 for
  • Replacement Air Ride Pin Box For A Fabex 765 Bolt Pattern
    The Trailair Air Ride 5th Wheel King Pin # UF35-946212 would be a compatible replacement for a Fabex 765 bolt pattern and is the only option that we currently offer for this pattern.
    view full answer...
    Image 1 for
  • Replacement Pin Box for 2008 Cameo 5th Wheel with 21K Fabex 765 Pin Box
    For your Fabex 765 pin box on your 2008 Cameo 5th wheel, I recommend the 5th Airborne Premium Fifth Wheel Air Ride Coupler # 5AB-E510-710 or the Trailair Air Ride 5th Wheel King Pin # UF35-946212. These are the only 21K pin box replacements we have for your specific pin box and capacity and both of these have the really nice air ride feature for a smoother ride and reduced jarring and chucking. With any of our products if there are used products available they will be listed on the product...
    view full answer...
  • Dimensions of Trailair Air Ride Pin Box for Fabex 750, 765 and 770, & RBW 7028
    I reached out to the manufacturer, Lippert, who was able to give me some of the dimensions you were looking for regarding the Trailair Air Ride 5th Wheel King Pin - Fabex 750, 765 and 770, RBW 7028 # UF35-946212. They didn't have the dimensions from the bolt holes, but were able to provide me with the spec sheet they did have, which shows the length, width, and height, which should be useful for you. As you can see by the accompanying cut out of the sheet, the Trailair Air Ride # UF35-946212...
    view full answer...
    Image 1 for Image 2 for
  • 5th Airborne Premium Fifth Wheel Air Ride Coupler To Replace RBW 7026
    In my research I was unable to find 7026 as one of the RBW model pin boxes. It's possible the last number has worn off and what looks like a 6 is really an 8. You may want to check the number again to make sure it that isn't the case. If you find you have a 7028, which is a fairly common one, the replacement is part # UF35-946212. If you can't make out the last number for sure, you will need to measure the mounting holes to find the right replacement. I have attached a helpful article...
    view full answer...
  • Hole Spacing & Width of Trailair Air Ride 5th Wheel King Pin for Fabex 750, 765 Pin Box
    The Trailair Air Ride 5th Wheel King Pin # UF35-946212 is a replacement for the Fabex 750 and 765 Pin Box; it has bolt hole spacing that is 9-1/2 inches apart horizontally and 2 inches vertically, and is 12-1/2 inches wide.
    view full answer...
  • Longest Available Trailair Replacement Air Ride Pin Box
    A replacement air ride pin box like what Trailair manufacturers will be specific to the OEM pin box on your fifth wheel. Your existing pin box should have a sticker or label on it that identifies the manufacturer and the model number of the pin box. In other words, if your existing pin box is a Lippert 1621HD, you would not be able to install a pin box designed to replace a RBW7019. When measured from the first row of mounting holes to the center of the king pin, the # UF35-946212 measures...
    view full answer...
  • Replacement for RBW 7028 Pin Box to Reduce Chucking and Improve Ride Quality
    The perfect solution to replace your RBW 7028 pin box is the Air Ride # UF35-946212. It greatly reduces vertical shock that is caused by traditional rigid pin boxes and protects your trailer by reducing the amount of vibration to the the frame, which is more than just an added bonus, it's a way to protect your investment.
    view full answer...
    Image 1 for
  • Replacement Pin Box for RBW 7028 on Trailer
    Since you have an RBW 7028 we do have a replacement pin box with the Trailair part # UF35-946212 but this is our only replacement solution for what you have at this time.
    view full answer...
  • 2011 Carriage Cameo Replacement Cushioned Pin Box Fit
    Yes, the Trailair cushioned pin box # UF35-946212 that you referenced is the correct fit for you as this is designed to replace the Fabex 770 that you have now along with a few other variations. This actually fits the following: Fabex 750, 765 and 770 RBW 7028
    view full answer...
  • Will Trailair Pin Box Collect Water on Top of It When Parked
    I spoke to my contact at Trailair and he said that the Trailair pin box is not waterproof, and therefore can fill with water when there are heavy rains. Subsequently, when the unit is moved, the water inside can slosh out. One way to prevent this from happening would be to drill a small hole, using a 1/8” to 3/16” drill bit into the bottom of the pin box to allow this water to drain if needed, instead of gathering inside it.
    view full answer...
  • Compatible Upgraded Pin Box Replacement For A MORryde RPB72-770-06 Pin Box
    The MORryde RPB72-770-06 Pin Box you have is a Fabex 770 bolt pattern so the Trailair Air Ride 5th Wheel King Pin # UF35-946212 that you linked to will be a compatible fit. This air ride pin box will offer you smooth, stable towing with your fifth-wheel trailer by replacing your ordinary pin box with an air-ride-equipped model. The scissoring action of the coupler allows the interior air bag to absorb road shock so that you won't feel it. When you encounter uneven terrain on your trip...
    view full answer...
  • Correct Ultra-Fab Trailair 5th Wheel King Pin to Replace the Mor/Ryde RPB72-770
    Since you have a Mor/Ryde RPB72-770 on your 2012 Carriage Cameo, this indicates that your trailer was originally set up for a Fabex 770 pin box. To replace a pin box on a trailer that originally came with the Fabex 770, Ultra-Fab offers the Trailair Air Ride 5th Wheel King Pin, # UF35-946212. Ultra-Fab does not make the Tri-Glide option for your trailer set-up.
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  • Trailair Cushioned Pin Box Recommendation for 2002 Forest River 27 with RBW 7028
    We have a Trailair cushioned pin box that works as a replacement for a RBW 7028, part # UF35-946212 but we do not have a Roto Flex at this time that fits your pin box. This is a great cushioned pin box though that will improve the overall ride quality quite a bit.
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  • Cushioned Pin Box Recommendation for 2007 Keystone Cougar with 1621 Lippert Pin Box
    From speaking to previous customers with a 2007 Keystone Cougar we have determined that your trailer has a Lippert 1621 pin box. That means that for a cushioned pin box you would want the Lippert pin box part # LC328492 which is a confirmed fit.
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  • Can Pull Rite Fifth Wheel Hitches be Used with Trailair Pin Boxes
    While we don't carry Pullrite Superglide hitches we are aware that they have a capture plate designed for use with the Trailair pin boxes like the # UF35-946212 that you referenced. It should be their part number 331758. I'd recommend double checking that with Pull Rite though.
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Do you have a question about this 5th Wheel Pin Box?


Info for this part was:

Employee Lindsey S
Written by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Kathleen M
Updated by:
Kathleen M
Employee Laura H
Updated by:
Laura H
Employee Chelsea B
Updated by:
Chelsea B
Employee Wilson B
Updated by:
Wilson B
Employee Mike S
Updated by:
Mike S

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