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Underbed Rail and Installation Kit for Demco UMS 5th Wheel and Gooseneck Trailer Hitches

Underbed Rail and Installation Kit for Demco UMS 5th Wheel and Gooseneck Trailer Hitches

Item # DM8551010
Retail:$698.99
Our Price: $495.79
You Save: $203.20
Fifth Wheel Installation Kit

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Shipping Weight: 76 lbs
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Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Underbed Mount Series (UMS) fifth-wheel and gooseneck hitches. No-drill frame brackets offer a simple installation. 1-800-940-8924 to order Demco fifth wheel installation kit part number DM8551010 or order online at etrailer.com. Free expert support on all Demco products. Great prices and Fastest Shipping for Underbed Rail and Installation Kit for Demco UMS 5th Wheel and Gooseneck Trailer Hitches. Fifth Wheel Installation Kit reviews from real customers.
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  • Reviews (14)
  • Q & A (0)
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Demco Fifth Wheel Installation Kit - DM8551010

  • Below the Bed
  • Demco
  • Custom

Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Underbed Mount Series (UMS) fifth-wheel and gooseneck hitches. No-drill frame brackets offer a simple installation.


Features:

  • Installation kit is designed for use with Demco UMS 5th-wheel and gooseneck trailer hitches
  • Underbed rails allow for complete access to truck bed when hitch is removed
    • No exposed rails
    • 4 Mounting holes sit flush with truck bed
  • Vehicle-specific design reduces installation time and requires less drilling than universal systems
    • No-drill brackets bolt onto the outside of your truck's frame rails
    • Crossmembers sit along top of frame rails, beneath bed
  • Sturdy, black powder coated steel resists corrosion
  • Rails and installation hardware included
  • Made in the USA


Specs:

  • Application: Demco Underbed Mount Series (UMS) 5th-wheel and gooseneck trailer hitches
  • 5-Year limited warranty


8551010 Demco Hijacker UMS Under Bed Rail Frame Bracket Kit

Replaces Demco DM8551002 and DM8551003

Installation Details DM8551010 Installation instructions

This Product Fits The Following Vehicles




Customer Satisfaction Score:


Customer Reviews

Underbed Rail and Installation Kit for Demco UMS 5th Wheel and Gooseneck Trailer Hitches - DM8551010

Average Customer Rating:  3.9 out of 5 stars   (14 Customer Reviews)

Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Underbed Mount Series (UMS) fifth-wheel and gooseneck hitches. No-drill frame brackets offer a simple installation.

by:

This product is nice but doesn’t line up with OEM placement of pucks.

Etrailer Expert

Sierra K.

8/23/2021

That is because this product only fits vehicles without The OEM Prep Package. You want something like this: Item # DM6194.



by:

The instructions provided with the hitch were very detailed and provided enough information for me to install it myself. I love having the mounting rails below the bed. the auto slide worked flawlessly. For the winter I left the hitch coupled with the trailer to keep my bed clear.



by:

Kit made for my rig and fit as described. Installation a little on the difficult side for your typical DIY'er.

Kirk C.

7/26/2020

The under bed kit is the best. Having the truck bed useful when not traveling is great. I use a small electric hoist and casters for lifting and moving so the weigh is no problem. Installation was a little on the difficult side but any experienced DIYer can handle it.



by:

Merchandise arrived in good condition. Nothing missing. The shipping carton was in terrible condition. It was torn open from shipping, however nothing was missing or damaged . The product will fill my needs to replace the above bed rails that don't leave a clean bed when fifth wheel is removed. This will fill the bill. Thanks to Etrailer this will work perfectly for my Demco hijacker fifth wheel. Shipment was quick delivery.



by:
2017 GMC Sierra 2500

First package was destroyed in shipping, all hardware was missing, called etrailer forgot her name ( sorry ) very polite. she ordered all the correct hardware needed and had it shipped out. Except for the shipping was very pleased with etrailer.



by:
2018 Chevrolet Silverado 3500

Once I mounted everything and figured out I had to switch passenger and drivers brackets everything was fine it worked out ok



by:

It arrived in two days. Great delivery.



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2012 Chevrolet Silverado



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14
14

See what our Experts say about this Demco Fifth Wheel Installation Kit

  • Recommended 5th Wheel Hitch for 2019 Chevy 2500HD Short Bed without OEM Pucks
    I recommend using the Demco Hijacker Autoslide # DM8550034 on your 2019 Chevy 2500 without the OEM prep package since the slider automatically activates, so there's no getting out of the vehicle required each time you may need to make a tight turn. I also really like that this gives you an under-bed mounting kit with the # DM8551010 so you'll still have a completely clear truck bed when you're not towing your 5th wheel. This hitch has an 18,000-lbs capacity but if you're in need of a larger...
    view full answer...
  • Parts Needed To Install Demco Autoslide 18K 5TH Wheel Hitch On 2019 GMC Sierra 2500 With UMS
    Yes, you do have the correct part numbers. For your Demco Autoslide 5th Wheel Trailer Hitch # DM8550034 the Side Plates # DM6003 are the part number 6003 you referenced. To mount on the Underbed Rail and Installation Kit # DM8551010 for your 2019 GMC Sierra 2500 you will need the Side Plates # DM6004.
    view full answer...
  • Install Instructions for Demco Fifth Wheel Rail Kit # DM8551002
    If you check out the video I attached below you'll see an install we did for the Demco rail kit part # DM8551010 on a 2016 Chevy Silverado 2500HD just like yours. This will walk you through the entire process and will be more helpful than the written instructions.
    view full answer...
  • Do 16k and 20k Fifth Wheel Hitches Connect to Same Size King Pin
    All of the fifth wheel hitches we carry are designed to fit the same size king pin on a trailer. A 16k hitch would work just as well to connect to a fifth wheel trailer as a 20k fifth wheel hitch. I attached a link to a page that has all of the 20k fifth wheel hitches we offer.
    view full answer...
  • Best Fifth Wheel Hitch Recommendation for a 2015 GMC Sierra 2500 Short Bed
    Since you have a short bed truck you are going to need to get a slider fifth wheel hitch to allow you to make tight turns. Since getting out and operating the slider every time you get to a parking lot can be a bit of a hassle I would recommend the Demco Hijacker AutoSlide part # DM8550022. This hitch will automatically slide back when making tight turns. If you are looking for the best setup this would be it. The rail kit you would want would be the underbed kit part # DM8551010 that...
    view full answer...
  • Recommended Rail Kit to Move the Demco Hijacker from 2008 Ford F-350 to 2016 Chevy Silverado 2500
    The only thing that you will need to change to be able to use the Demco Hijacker 18K # DM8550022 on your 2016 Chevrolet Silverado 2500 is a new underbed rail and installation kit. Since the chassis on a 2008 Ford F-350 and a 2016 Chevrolet Silverado 2500 are different, you will need to use a different installation kit. The kit that you will need to use for your Silverado is part # DM8551010. I also recommend installing a 5th wheel and gooseneck wiring harness. Curt has a 7-Pole Harness,...
    view full answer...
  • Recommended Sliding 5th Wheel Hitch for 2019 GMC Sierra 2500 Duramax
    I recommend using the Demco Hijacker Autoslide # DM8550037, which has a 21,000-lbs capacity and can be adjusted between 15-1/2 - 18-1/4 inches tall. This is an automatic sliding hitch, so there won't be any need to get in and out of the vehicle each time you need to perform a tight turn that might otherwise have your trailer getting a little too close for comfort to the truck cab. You will need to use the custom installation kit # DM8551010 to provide you with the mounting rails for the...
    view full answer...
  • Auto Sliding Fifth Wheel Hitch for 2017 Chevy Silverado 2500 Short Bed without OEM Rail Kit
    We don't carry the Pullrite brand of hitches but we do offer an auto sliding hitch setup that will work just as good if not better than the Pullrites which aren't height adjustable. The Demco Hijacker AutoSlide part # DM8550037 is a really great auto sliding hitch that is a little easier to install and use than the Pullrite too since it doesn't require a capture plate. It also has a 21k trailer towing capacity. This installs in an underbed rail kit for your truck with part # DM8551010...
    view full answer...
  • Recommended 5TH Wheel Hitch With Underbed Rails For a 2016 GMC Sierra 2500 Short Bed
    I recommend the Demco Hijacker Autoslide 5th Wheel Trailer Hitch # DM8550022 for your 2016 GMC Sierra 2500 short bed. This hitch is rated for 18,000lbs and will automatically slide away from your truck as you turn, ensuring that your truck cab and trailer do not come into contact when you are trying to maneuver your 5th wheel trailer. And since it does it automatically you will not have to get out of your truck to reposition into a maneuvering position. The hitch will work with most 12"...
    view full answer...
  • Demco Hijacker Autoslide Underbed Fifth Wheel Trailer Hitch on 2016 GMC Sierra 2500
    For your 2016 GMC Sierra 2500 with a 6-1/2 foot bed the Demco Hijacker Autoslide # DM8550022 is the underbed fifth wheel hitch you'll want. It installs with the Custom Underbed Rail and Installation Kit # DM8551010. The Hijacker is an autoslide that will travel up to 14 inches. With many sliding hitches you need to get out of your truck to adjust the slider, make your turn, and then adjust it back to continue towing. With the Hijacker it will automatically slide when you're making your...
    view full answer...
  • Best Fifth Wheel Hitch Recommendation for 2017 Chevrolet Silverado 3500 Short Bed
    For your 2017 Chevy Silverado 3500 with a 6-1/2 foot bed the best fifth wheel hitch setup we have is the Demco Hijacker Auto Slide part # DM8550037. Since you have a short bed truck you have to have a slider hitch to allow you to make tight turns. Since most slider hitches make you get out and manually operate them the benefit to the Demco is that it does this automatically as you turn saving you the hassle. Then for a rail kit you'd want the part # DM8551010 which is a custom fit underbed...
    view full answer...
  • Are There Replacement Brackets For DM8551010
    The brackets and hardware are not available as separate purchases, so you would need to get the full kit, which is the Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches # DM8551010. I have added a link below to a video install for you to check out as well if you'd like to take a look.
    view full answer...
  • Recommended Sliding 5th Wheel Hitch for a 2015 Chevrolet Silverado 2500HD Short Bed
    I have two great options for your 2015 Chevrolet Silverado 2500HD; one that is easy to use as it operates automatically, the Demco Hijacker Autoslide 5th Wheel Trailer Hitch part # DM8550022 with the Underbed Rail and Installation Kit part # DM8551010 or one that is easier to remove, the Curt A16 5th Wheel Trailer Hitch part # C16521 with the Curt Custom Fifth Wheel Installation Kit part # C16411-204. The Demco Hijacker is great because you don't have to get in and out of the truck to...
    view full answer...
  • Is Demco Hijacker Autoslide Hitch Solid Hitch for 2015 Chevy Silverado 2500HD Short Bed
    The Demco Hijacker Autoslide part # DM8550034 is a really great, solid hitch that makes towing a fifth wheel trailer with a short bed truck much easier since you don't have to get out and operate the slider mechanism. To install it in your 2015 Chevy Silverado 2500 short bed would only require you to install the Demco rail kit part # DM8551010 and you'd be set.
    view full answer...
  • 5th Wheel Trailer Hitch and Install Kit for a 2016 GMC Sierra 2500 Long Bed
    First you will need an installation kit to mount the 5th wheel hitch in your 2016 GMC Sierra 2500 long bed. There are kits with rails above the bed and kits below the bed. The advantage of below the bed is that the bed is clear when the hitch is removed. If you want to go with above the bed rails I recommend Reese custom installation kit # RP56001-53. There is no drilling required to install the frame brackets and the longer rails and outboard frame brackets make installation much easier...
    view full answer...
  • Gooseneck Adapter that Fits Demco UMS Underbed Rail Kit of GMC Sierra
    For the UMS underbed fifth wheel rail kit you have installed in your 2015 GMC Sierra 2500 all you'd need is the part # DM5988 and you'd be set.
    view full answer...
  • Installing Demco 5th Wheel Underbed Rails Compatible with Demco 8550022 Fifth Wheel Hitch
    For your Demco Hijacker Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs # DM8550022 the Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches # DM8551010 will work well. I've attached the installation details to help you determine the mounting to your frame which will then give you the correct bed locations. I've attached a drawing from the installation instructions as well as the complete instructions to assist.
    view full answer...
    Image 1 for
  • Demco Underbed Rail System Dimensions for a 2016 GMC Sierra 2500
    Thanks for the picture! Those holes are not from an OEM puck system because the cab to tailgate dimensions are too short. It looks like the previous owner used the Underbed Rail and Installation Kit for Demco UMS 5th Wheel Hitches item # DM8551010. This system worked similar to an OEM puck system but only with Demco hitches. I have linked a dimensional drawing below for you to compare to what is currently on your truck. I have also attached an installation video. Since your 2016 GMC Sierra...
    view full answer...
    Image 1 for Image 2 for
  • 7-Way Trailer Wiring Connector for Bed of 2016 GMC Sierra 3500
    Sounds you are referring to 7-way wiring ran to the very rear of the truck near the bumper. So what you would need to install a 7-way in the bed of the truck is the 5th wheel 7-way wiring kit part # 50-97-410. This plugs inline to that connector and gives you a harness and 7-way that will reach up to the wheel well. I attached an install video for this kit on a 2016 GMC Sierra 3500 just like yours as well.
    view full answer...
  • Are there Covers for the Holes in Underbed Rail and Installation Kit # DM8551010
    There are no covers for the holes for the Underbed Rail and Installation Kit # DM8551010. That means that it is possible for debris to get in the holes. If that happens and it affects the fit of the hitch then I recommend using compressed air to clear out the debris.
    view full answer...
  • Installation of UMS Demco 18K Auto Slide Base Rails on a 2015 GMC 2500 Sierra Diesel Crew Cab
    I took a look at the directions and they are straight forward and provide clear diagrams. According to them there may be the need to trim the heat shield on some models but they provide another excellent diagram showing exactly where to trim if this is needed for your truck. I have linked a few images for you to check out. They also recommend lifting the trucks rear end for better access to install base rails. The manufacturer does offer two methods of install based on your situation. Estimated...
    view full answer...
    Image 1 for Image 2 for Image 3 for
  • How to Tell if 2016 Chevy Silverado 2500 Has Factory Rail Kit for Fifth Wheel Hitch
    Most likely you would know if you had the Factory Rail Kit in your 2016 Chevy Silverado 2500. There would be holes in the bed of your truck that the feet of a fifth wheel hitch would fit into. I attached a picture that shows what they pucks/holes would look like. If you have them the B and W Hitch part # BWRVK3700 that you referenced would fit and work well. Otherwise for an underbed fifth wheel hitch setup I would recommend the Demco Hijacker part # DM8550022 which will automatically...
    view full answer...
    Image 1 for
  • 5th Wheel Trailer Hitch and Installation Kits for a 2015 Chevy Silverado 2500
    I will be happy to make some recommendations for your 2015 Chevy Silverado 2500. If the truck is a short bed then I recommend custom underbed mount kit # DM8551010 with the 21,000 pound rated auto-sliding HiJacker, # DM8550037. The underbed mount means that the bed will be clear when the hitch is removed for a clean look and a bed free of obstructions. The hitches slide automatically so you won't have to get out of the truck. And they travel 14 inches, the most of any slider we have, for...
    view full answer...
  • Underbed Demco Hijacker Hitch and Rail Kit Recommendation for 2016 GMC Sierra 3500
    There is a great underbed rail system that Demco offers for their Demco Hijacker Autoslide hitches. The rail system you'd need for your 2016 GMC Sierra without the factory rail kit is the part # DM8551010. Then for a hitch you'd need the part # DM8550022 for the 18k version or the part # DM8550037. The Trailair pin boxes can be used with the Demco Hijacker but not the RotaFlex. To use one with a Mor/Ryde pin box requires the locking plate part # DM6025.
    view full answer...


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Info for this part was:

Employee Joe V
Test Fit:
Joe V
Employee David F
Test Fit:
David F
Employee Lindsey S
Edited by:
Lindsey S
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Dustin K
Video by:
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Employee Kristina F
Written by:
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Employee Noah M
Updated by:
Noah M
Employee Carrie F
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Employee Justice A
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Employee Andy C
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