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  1. Fifth Wheel King Pin
  2. CURT
  3. Lippert 1116
  4. 19000 lbs GTW
  5. Upgraded Pin Box
  6. Absorbs Road Shock and Reduces Chucking
Curt Rota-Flex 5th Wheel Pin Box - Lippert 1116 - 19,000 lbs

Curt Rota-Flex 5th Wheel Pin Box - Lippert 1116 - 19,000 lbs

Our Price: $705.35
You Save: $379.50
Fifth Wheel King Pin
Shipping Weight: 119 lbs
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This Rota-Flex pin box has a pivoting head with a built-in rubber compound that works to reduce chucking and absorb road shock, resulting in a smoother ride and less wear and tear on your trailer. Replaces Lippert 1116 pin boxes. 1-800-940-8924 to order CURT fifth wheel king pin part number LC176440 or order online at Free expert support on all CURT products. Great prices and Fastest Shipping for Curt Rota-Flex 5th Wheel Pin Box - Lippert 1116 - 19,000 lbs. Fifth Wheel King Pin reviews from real customers.
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  • Reviews (28)
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CURT Fifth Wheel King Pin

  • Lippert 1116
  • 19000 lbs GTW
  • Upgraded Pin Box
  • CURT
  • Absorbs Road Shock and Reduces Chucking
  • Fixed Turret

This Rota-Flex pin box has a pivoting head with a built-in rubber compound that works to reduce chucking and absorb road shock, resulting in a smoother ride and less wear and tear on your trailer. Replaces Lippert 1116 pin boxes.


  • Pivoting pin box replaces standard pin box on your 5th-wheel trailer to improve handling and limit strain on the truck and trailer
    • Minimizes chucking by allowing controlled movement of king pin within your hitch
  • Rubber compound built into the head absorbs road shock
    • Reduces wear and tear on trailer
  • Black powder coat provides rust resistance
  • Sturdy steel construction
  • King pin connects to any 5th-wheel trailer hitch
  • Bolt-on installation with no assembly required
  • Made in the USA


  • Designed to replace Lippert 1116 5th-wheel pin box
  • Weight capacity: 19,000 lbs
  • 1-Year limited warranty


  • Do not use the Curt Rota-Flex pin box with any type of gooseneck adapter.
  • The Curt Rota-Flex is not compatible with Curt Q-Series 5th wheel hitches.

The Rota-Flex pin box has a pivoting head and built-in rubber compound that help to reduce checking and absorb road shock for a smoother ride as you tow your fifth-wheel trailer.

Pivoting Head Reduces Chucking

The Curt Rota-Flex pin box has a pivoting head to help reduce chucking

The pivoting head on the Rota-Flex allows for controlled back and forth movement of the king pin to reduce the uncomfortable jarring known as chucking. Unlike a rigid pin box that has little give at the point where the trailer and the hitch are connected, the Rota-Flex can pivot slightly to compensate for those times that your trailer suddenly pushes or pulls on your tow vehicle. Because the pin box head - not the king pin itself - is moving, the chucking that often occurs when the king pin jerks around inside the hitch is significantly reduced.

Rubber Compound Absorbs Road Shock

The Curt Rota-Flex pin box has a built-in rubber compound to help absorb road shock

A heavy-duty rubber compound is built into the head assembly of the Rota-Flex pin box. This rubber absorbs the bumps and vibrations, or road shock, experienced when towing a fifth-wheel trailer over rough roads. Standard pin boxes without any type of shock absorption transfer road shock to your trailer, resulting in potential damage to the trailer and an overall bumpy ride. The shock-absorbing rubber inside the Rota-Flex takes the beating so there's less wear and tear on your trailer or RV and you get a smoother ride.

Easy, Bolt-On Installation

The Rota-Flex is easy to install. Simply remove your existing Lippert 1116 pin box and install the Rota-Flex on your trailer or RV. The Rota-Flex uses the same bolts that held on your original pin box so no additional hardware is required. Plus, it comes out of the box ready to be put on your trailer, so no assembly is needed. Because the Rota-Flex is quite heavy, you should put it on an elevated surface or have a friend help you support its weight during installation.

176440 Curt Rotaflex Fifth Wheel Kingpin Box for Lippert 1116

Replaces 176440 Lippert Components (LCI) Rotaflex by Trail Air Fifth Wheel Kingpin Box for Lippert 1116

Item # LC176440

Customer Satisfaction Score:

Customer Reviews

Curt Rota-Flex 5th Wheel Pin Box - Lippert 1116 - 19,000 lbs - LC176440

Average Customer Rating:  4.6 out of 5 stars   (28 Customer Reviews)

This Rota-Flex pin box has a pivoting head with a built-in rubber compound that works to reduce chucking and absorb road shock, resulting in a smoother ride and less wear and tear on your trailer. Replaces Lippert 1116 pin boxes.


It's a great pinbox. Really helped with chucking and compatible with my Demco sliding hitch. Also no issues with delivery, was helped by Pam and Jessie. They are awesome people to work with.


Perfect replacement for my unit. The movement in the mount helps with the shock on the hitch itself. The unit is very strong and after a year I have had no problems. The instructions were spot on and shipping was very fast. I recommend this pin box as it is more economical than others I have seen but really helps on the bump and pull with a solid hitch



This unit is working as perfect as it did when new. Simple with no bags to inflate or check on. Great product and I would recommend this to anyone.


Got it on and ready to try. It fit nicely. Did it myself in about an hour . Nothing left of the box it was in but other than a couple of scratches the pin box itself was in good condition


Product was as ordered. Hat's off to etrailer. After UPS lost the first one, etrailer expedited its replacement


I installed this by myself (it is heavy!) by putting it in the bed of my pickup & strapping it to a floor jack but not a job I’d recommend doing it by yourself.
I already have airbags on the rear axle of my pickup is why I chose this king pin . Only a 200 mile trip and the bucking on the 5th wheel was gone. But the real test will be on a rough highway...


Have not installed yet, paint has been scraped off in several locations especially on top and on the rounded corners from shipping. Will have to do some touch up painting. Excited to get installed and pull trailer next weekend


The pin box made the 5th wheel handle better, with less chucking and very stable.


Definitely dampened the chucking and my wife is much happier with the ride. Also it seems to be much quieter. Noticed at the camper show many units come with the Roto flex from the factory.


The hitch arrived poorly packaged in a cardboard box. The hitch is very heavy. It was scratched and required repainting.

The hitch itself looks well made and strong.


Looks and works great. Easy install


It did what it was advertised to do.


Great product, Installed and what difference the ride. Thanks SJ McDonnell



Great hauls good thanks


Works great eliminated the jaring. Also shorter so I can make a hard turn without touching the sides of my box


The cardboard box the hitch was delivered in was damaged, hitch was not damaged. Curt could potentially package the hitch differently to protect the product and mitigate delivery damage.


The shipping container was not adequate for pin box. It was too large and no protective packing was used to protect the powder coated finish. When it was delivered by UPS the carton was destroyed. I had to repaint it as it was badly chipped from rough handling. I am disappointed in the performance as I do not see any difference in the chucking which is the reason why I purchased it. If I were to get a different 5th wheel I will not purchase a Rota-Flex again.


Received on Wed. as planned. With a little help from my forklift, I had this trail air pin box installed in few hours. Fit perfect on my Sabre. Drove around the block, about 4 miles. This pulls so nice, it is like nothing behind you. Thanks etrailer.


Looks great on my 5th. If anyone else has wondered as I did and could not find anything online regarding the vertical height difference between this trail air rota flex and my standard lippert 1621. This pin box will reduce the nose of my 5th by 2" mounted in the same location. Now to pull my rear axle spacers on my dodge to get another 1.5" lower. Etrailer is great as always. Never had a problem with them and have ordered here many times. Thanks Etrailer!


> haven taken trip yet but i know there be a huge difference in the ride


The product was great, The better part was how fast it got to me . I had it put on the camper the same day i had received it what was 3 days after my order. Now you can't beat the shipping. All my orders from ETrailer has been fast and on time . Thank you all at Etrailer.


I was surprised at the difference one product could make in my towing experience! It really helped the chucking.


Haven't installed pin box yet but it was delivered uncrated, and it looked like it was a used pin box.


The difference now compared to when I had my done is like night and day, no more chucking, very little if any jarring , the ride meets al my expectations


Fast shipping and item fits perfectly. Replaced old pin box by myself with a small tractor in about 45 minutes. Can't wait to try it out on my new toy hauler.


A noticeable improvement over the standard pin box. It's most obvious when starting and stopping. It was very easy to install even for two 60+ women. We're happy with the purchase.


The Trailair Roto-Flex is an excellent product. It really has smoothed out the ride and handling of my fifth wheel, especially over roads that aren't so perfect. I highly recommend this for an upgrade.

Show More Reviews

See what our Experts say about this CURT Fifth Wheel King Pin

  • Can Rota Flex Pin Box be Used with Reese 16k Fifth Wheel Hitch
    Your Reese 16k hitch would easily work with the Rota-Flex pin boxes like # LC176440 without issue. The ability of the hitch head to pivot would not be a problem for the Rota Flex. This is true for all Reese hitches.
    view full answer...
  • Is RotaFlex Pin Box Similar to Mor Ryde Pin Box In terms of Cushioning
    The Mor/Ryde pin boxes and the Trailair RotaFlex like part # LC176440 are pretty similar in how they cushion the ride. The Mor/Ryde is definitely more common out there on the road, but the feedback I've read on people who have tried both said they were very similar.
    view full answer...
  • Is Rotaflex or MORryde Pin Box Better for Keystone Montana
    The ride quality between the MORryde and the Rotaflex pin boxes are about equal. I did some digging and the Keystone owners seem to mostly like both of them about the same. Some people preferred one over the other but in general I would say you aren't going to see a huge difference. One thing that was mentioned with the Rotaflex was that it squeaks a bit though.
    view full answer...
  • Matching Pin Box for Replacing With Trailair Rota-Flex 5th Wheel Pin Box
    The Trailair Rota-Flex 5th Wheel Pin Box - Lippert 1116, # LC176440, is designed to be a direct replacement for the Lippert 1116 pin boxes, if you have a 1116 pin box then this will fit. Please see attached image for bolt pattern and note the attached video for visual in points of measurements. I am uncertain what specific measurement you are wanting but this video covers multiple points across the three rows on this pin box plus width and length.
    view full answer...
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  • What Is The Torque Specs For The Curt Rota-Flex Pin Box?
    For the Curt Rota-Flex 5th Wheel Pin Box # LC176440, Curt recommends to reuse the old hardware that was removed from the original pin box, unless they are damaged or unusable. The torque spec is dictated by the type of bolt that is used along with the type of metal it is made of. For example, if you have 1/2"-13 grade 5 zinc plated bolts, then the proper torque spec is, 65 ft-lbs. I have attached a chart that expands upon this, provided by Curt.
    view full answer...
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  • Determining The Pin Box Bolt Pattern Of A 2019 Keystone Montana 3791 RD With The Pin Box Tag
    Thank you for the pictures, you have a Curt Rota-Flex 5th Wheel Pin Box - 19,000lbs # LC176440 with a 1116 bolt pattern so the Trailair Air Ride 5th Wheel Pin Box - Lippert 1116 - 21,000lbs # LC155943 you were wanting to install will be a compatible fit.
    view full answer...
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  • Comparing The Trailair Rota-Flex 1116 And Trailair Air Ride 1116 Pin Boxes
    The Trailair Air Ride 5th Wheel Pin Box - Lippert 1116 - 21,000lbs Item # LC155943 has two different placements when installing but as you can see in the attached dimension spreadsheets it has an overall height of 17-7/16" whereas the Trailair Rota-Flex 5th Wheel Pin Box - Lippert 1116 - 19,000lbs Item # LC176440 only has an overall height of 11.05". The # LC155943 is going to sit higher but you also need to make sure you aren't raising too much and placing your camper out of level as this...
    view full answer...
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  • Best Cushioned Pin Box for 2019 Keystone Sprinter Limited with Lippert 1116 Pin Box
    For your 2019 Keystone Sprinter Limited Fifth Wheel trailer that has a Lippert 1116 pin box installed on it currently the best cushioned upgrade option we have is the Trailair part # LC155943 which uses an air bag and shock to cushion bouncing and jarring. This option will do the best to cushion the ride quality and also has more capacity than you'd need as it's rated for 21,000 lbs trailer weight.
    view full answer...
  • Cushioned Pin Boxes that Fit in Place of 1116 Style Pin Box
    Since you have the 1116 style pin box the correct Rota Flex replacement would be the part # LC176440. The 1621 style pin boxes like what you mentioned are not interchangeable with the 1116 style. Or for a Trailair you'd want the part # LC155943 but we do not have a Flex Air that fits.
    view full answer...
  • Trailair Rota Flex Cushioned Pin Box that Fits as Replacement for Fabex 665
    The cushioned Trailair Rota-Flex 5th Wheel Pin Box # LC328330 does fit the Fabex 665 that you have now and would work great as a cushioned replacement. While this pin box states it's designed to fit as a replacement for the Lippert 1621 or 1621HD we've found that in general the 1621 and the Fabex 665 are identical.
    view full answer...
  • Pin Box Solution for Trailer With Lippert 1116 To Gain Additional Turning Clearance
    If you need additional pin box length for turning clearance with your trailer that has a Lippert 1116 pin box we have a great solution, but the Rota-Flex you mentioned does not provide additional turning clearance so it would not be the way to go. Instead what you'd want is a Sidewinder pin box # RP61412 which moves the pivot point back 22 inches so that even with super short truck beds you'll have the clearance needed to make tight turns.
    view full answer...
  • Slider Companion Hitch Recommendation for Short Bed Truck with Turnover to Allow Turning Clearance
    The Rota-Flex part # LC176440 would fit as a replacement on your trailer that has a Lippert 1116 on it currently. But this product has the same dimensions as your current pin box. These are designed to be basically exact replacements that are cushioned. Extending a pin box out further than what the trailer had can put added stress on the trailer's frame due to the increased leverage. The only solution we can offer is to replace your Companion hitch with the sliding Companion part # BWRVK3400....
    view full answer...
  • Best Pin Box Replacement Solution for Fabex 765 to Provide Additional Turning Clearance
    Sounds like you are looking for a pin box replacement solution that will give you additional turning clearance since you are wanting the king pin out an additional 6 to 8 inches. For your Fabex 765 we actually have a really great solution for that with the Sidewinder part # RP61412 which moves the pivot point back 22-1/2 inches and essentially gives you 22-1/2 inches of additional cab-to-trailer-nose clearance. This is the ultimate pin box replacement solution for giving additional clearance....
    view full answer...
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  • Best Pin Box Replacement for Turning Clearance to Replace Lippert 1116 Pin Box
    The Lippert 1116 pin box is a medium length pin box and there isn't an extended version available that would replace it. If you are needing additional turning clearance the way to go is with a Sidewinder since it moves the pivot point back 22-1/2 inches to provide the clearance. For that you'd just need the part # RP61412 and you'd be set. Sidewinders also help make the trailer easier to back up as well as track better behind the truck when towing.
    view full answer...
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  • Recommended Pin Box to Replace Lippert 1116 for Added Cab Clearance
    The Trailair Rota-Flex 5th Wheel Pin Box # LC176440 that you referenced will work well to provide a more comfortable ride but it won't help with the cab clearance issue you're having with your short bed truck. The dimensions on the pin box will be fairly similar to your existing Lippert 1116 pin box, which is what this is designed to replace. If you have a Lippert 1116 model pin box the best solution for adding both the needed turning clearance and a more comfortable ride is with the...
    view full answer...
  • Which Trailair Air Ride Pin Box Replaces Roto-Flex 1116 Pin Box on 2018 Keystone Raptor 355TS
    Thanks to the item number from your current pin box my contact at Lippert was able to confirm that your 2018 Keystone Raptor 355TS has a Trailair Rota-Flex 5th Wheel Pin Box - Lippert 1116 # LC176440 which has a 19000lb weight capacity and uses the 1116 bolt pattern. You will need the Trailair Air Ride 5th Wheel Pin Box - Lippert 1116 # LC155943 is designed to replace your 1116 bolt pattern pin box and offers a 21000lb weight capacity. This pin box will offer a much smoother ride due to...
    view full answer...
  • Which Trailair Rota-Flex Pin Box Compatible with Lippert 1621 Pin Box
    I have a solution for you, but the Trailair Rota-Flex # LC176440 pin box is designed to replace 5th wheel trailers with a Lippert 1116 pin box and not the 1621 pin box. Instead, you'll want to use either the # LC328330 (trailer with GVWR of less than 18000-lbs) or the # LC328329 (trailer of GVWR less than 21000-lbs). The Trailair Rotaflex is a great solution to help reduce the bouncing and jarring that car be experienced with an uncushioned pin box and will be a great upgrade for your towing...
    view full answer...
  • Is Trailair Rota-Flex Pin Box Available in 12-3/8 Inches Wide?
    The Trailair Rota-Flex 5th Wheel Pin Box - Lippert 1621 or 1621HD -18,000 lbs # LC328330 and the 21,000 lbs # LC328329 are 12-1/2 inches wide. The sizes of pin boxes for width are simply 12 inches or 12-1/2 inches so you would definitely want the 12-1/2 inch pin box. You will want to check your current pin box number which should be on a sticker on the actual box itself. If not there, you will want to measure your mounting bolts to ensure the correct fit. I've attached an article...
    view full answer...
  • Replacement Sidewinder Pin Box for Lippert/Trailair Rota-Flex 1116 Pin Box
    I reached out to my contact at Lippert who said that the current Rota-Flex you have on your 5th wheel trailer is the part # LC176440 which is rated for 19K and pin box number 1116. The correct Sidewinder replacement is part # RP61412 on our site which is rated for 16K. This comes with a universal wedge to lock out the king pin but if you can tell me what 5th wheel hitch you have I can let you know if there are any custom wedges that would offer a better fit. Please also note the attached...
    view full answer...
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  • Recommended Pin Box Upgrade for 5th Wheel Trailer with Lippert 1116 Pin Box
    I recommend using the TrailAir Ride5th Wheel Pin Box # LC155943 which is compatible with your Andersen Ultimate # AM3200. The TrailAir Ride provides the ultimate solution to reduce jarring and bouncing when towing a 5th wheel trailer and will work as an OEM replacement for your Lippert 1116 pin box.
    view full answer...
  • What Replacement Pin Box do You Recommend to Use with a Curt Q16 and a Lippert 1116?
    I went ahead and reached out to my tech at Lippert (who designed the Rota-Flex # LC176440 for Curt), and they confirmed that the reason why Curt E series and Curt Q series hitches like the Curt Q16 is not compatible with the Rota-Flex is because the articulating movement of the hitch interferes with the pivoting movement of the pin box. These two mechanisms work against each other. With that being said, if you have the Lippert 1116 pinbox, a great alternative that does not have a pivoting...
    view full answer...
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  • Recommended Replacement For An 1116 Pin Box And Turning Clearance Recommendations
    Since you don't want the an Air Ride pin box I recommend the Trailair Rota-Flex 5th Wheel Pin Box - Lippert 1116 - 19,000lbs Item # LC176440. There's only about a 1-2" difference between different 1116 style pin boxes. This Rota-Flex pin box has a pivoting head with a built-in rubber compound that works to reduce chucking and absorb road shock, resulting in a smoother ride and less wear and tear on your trailer. Normally I would say to use a sidewinder or slider to gain turning clearance...
    view full answer...
  • Recommended Upgraded Pin Box For A 2017 Keystone RV Raptor 5th Wheel Toy Hauler 425TS
    The Rota Flex pin box comes in either a 1621 # LC328330 or 1116 # LC176440 bolt pattern. For an upgrade I recommend the Trailair Flex Air 5th Wheel Pin Box # LC369535 for a 1621 bolt pattern or the Trailair Air Ride 5th Wheel Pin Box # LC155943 for a 1116 bolt pattern. These pin boxes are both rated for 21,000lbs to ensure you safely tow your 2017 Keystone RV Raptor 5th Wheel Toy Hauler 425TS with a 15860lbs dry weight. The Flex Air drastically reduces chucking, absorbs road shock, and...
    view full answer...
  • Is Curt Q20 Sliding 5th Wheel Hitch on Ram 3500 Compatible with Rota-Flex Pin Box
    Thank you for reaching out - I'd be more than happy to clear up any confusion! The Rota-Flex pin boxes, like part # LC176440, are NOT compatible with the E-Series and Q-Series Curt 5th wheel hitches because they have a spherical head which won't be stable enough to work with the Rota-Flex cushioning design. So if you really like the Curt 5th wheel hitch design you need to either swap out your pin box or you need to use the A20 Curt hitch which has a torsion head that is compatible with...
    view full answer...
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Info for this part was:

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