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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 # DM8551000
Retail:$780.19
Our Price: $587.74
You Save: $192.45
Fifth Wheel Installation Kit

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Shipping Weight: 48 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 DM8551000 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 (26)
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Demco Fifth Wheel Installation Kit - DM8551000

  • 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


8551000 Demco Hijacker UMS Under Bed Rail Frame Bracket Kit

Installation Details DM8551000 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 - DM8551000

Average Customer Rating:  4.7 out of 5 stars   (26 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:
Ford Transit Connect

Great product , easy to understand instructions, and a perfect fit. Customer service was also top notch had a problem with the first order missing rail fell out of the box in transit , no fault on etrailer, they sent me a new order before the old one was picked up! Fantastic customer service, I will definitely order from etrailer again!

Wil K.

2/17/2020

Everything has been working great, no problems at all!



by:
2014 Ford F-250 and F-350 Super Duty

The under bed rail kit was easy to install. It provides easy removal and installation of the Demco Autoslide 5th wheel hitch. I could not be more pleased with the Demco products. I recommend getting the Demco 5th Wheel Lifting Bracket
Item # DM6100. It makes removal and installation of the hitch a breeze.



by:
Ford F-350 Super Duty

Instructions left alittle to interpretation when it came to hitch height in the bed of the truck. For a f350 super duty it is the medium set up. Save you some time and effort. Other then that it looks great and will be testing it out this weekend.



by:

It’s a pleasure doing business with your company and getting products in a timely manner.

Stanley

8/2/2023

Don’t have problem with parts , it is the service . The first time I ordered everything went great and on time . The bext time I ordered all my parts wasn’t there , I was told I would receive missing parts the day day before my travel . Then I get confirmation email that I was gonna receive my parts two days after my leave date to be told there isn’t anything they could do . Why should I lose out on my week stay in key west at a night because they didn’t send me my parts I ordered way before my leave date .



by:
2006 Ford F-250 Super Duty

Only issue I ran into with my truck is that using the supplied measurements the back holes hit 1/4 on the bed rail. Still large enough to install the cross bars and hitch but something to be aware of. Truck was a 2006 F250 lariat 2wd with 6.5 box



by:

Not to difficult to install. It will require 2 people to get the bolts torqued down. Handles a 14000 lb fifth wheel with ease



by:

The under bed mount for the demco auto slide was easy to install with easy instructions and works great

Tony C.

7/9/2018

The under bed rails and Demco hitch are great. I have put 20 thousnd miles on them with 13,654 pounds of fifth wheel trailer



by:
2006 Ford F-250 and F-350 Super Duty

Hitch appears to be well-constructed and sturdy. I have not yet installed it. Some assembly is required, and the instructions aren't crystal clear. Better illustrations would be helpful. The videos online are the best source of installation information. Shipping materials lack protection. The powder coating was damaged in a few locations, as well as the instructions. I expect the hitch will operate exactly as designed a long as I protect the exposed parts from the inevitable elements. Rubber grommets would be a nice addition to the holes drilled in the truck bed.



by:

Perfect fit. Planned ahead and had put on an Airlift 5000 with the auto level system. Adding this under bed mount for my hijacker auto slide on my 2015 F250 was simple and bolted right up with my airbags.

etrailer customer service was great in helping me make sure all the parts I ordered won’t play nice together.



by:
2013 Ford F-350 Super Duty

Easy to install.

Darin

3/11/2023

This hitch has been working flawlessly for the past year. I would definitely recommend this hitch to anyone that is looking for a great sliding fifth wheel hitch.



by:
2008 Ford F-350 Super Duty

Installed the kit on my 08 ford f350 srw crewcab diesel. Fit fine. Well made. I just think the passengers side center bolt washer/extension piece was welded on the wrong side. I did a backyard fix , buy cutting a small filler piece out of steel so the frame plate wouldn't suck up to the frame and bend. Otherwise, good strong steel



by:

Timely delivery. Product was very well packaged. All parts where clearly marked and instructions are well writen.



by:

worked perfect.no drilling! well worth buying this instead of the universal kit. and no rails in the bed!

Buddy R.

3/24/2019

great!



by:

Great design. Installation wasn't bad at all (plan on buying a carbide drill bit). Hole plugs just cheap plastic.



by:

Arrived on time and in good condition. Instructions were good a bit hard to install on drivers side. But that’s the truck not the part. Part had no issues with fit



by:
2012 Ford F-250 and F-350 Super Duty

Just as described. Install was very easy.it had one base rail missing and called and talked to Sheila and she sent another one out. Had to set up our camper for a new job we are starting and needed the part in two days. She overnighted it and it was here on time.
Rod



by:
2012 Ford F-250 and F-350 Super Duty

Excellent product, it is fairly easy to install.



by:
2008 Ford F-250 and F-350 Super Duty

Great product, drill 4 holes and you are done, simple.



by:

Was easy to install with very few tools.



by:

Same as one



by:
1999 Ford F-250 and F-350 Super Duty

nice product fit was good. prompt shipping.



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Show More Reviews

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

  • Recommended 5th Wheel Hitch for 2016 Ford F-350 and 21,000 Pound Trailer
    We do have a nice selection of fifth-wheel hitches that use under bed rails for the 2016 Ford F-350. The Firestone Ride-Rite Red Label Air Helper Springs # F2703 that you also mentioned installing are compatible with the mounting hardware from an in-bed hitch. We do not currently carry Pull-Rite products. The highest rated under bed fifth-wheel hitch we have available for your truck is the Demco Hijacker Fifth Wheel Hitch # DM8550032 if you have the 8 foot bed or the Hijacker Slider #...
    view full answer...
  • Will the Demco Underbed Rail Kit work with the 18,000 lb Capacity Sidewinder on my 2012 Ford F350
    With one small change absolutely. You just want to change the part # DM8550024 to the Demco Hijacker Autoslide 5th Wheel Trailer Hitch w/ Slider part # DM8550022 this one is specifically designed and will work out great with the Underbed Rail and Installation Kit part # DM8551000 from Demco. It retains the 18,000 lb. capacity you originally inquired about it is the exact same thing just designed for Demcos's base rather than Ford's
    view full answer...
  • Under Bed Fifth Wheel Rail Kit Recommendation for 2001 Ford F-350 Short Bed
    I attached a link to this page that has all of the under-bed fifth wheel hitch solutions we have for your 2001 Ford F-350 short bed. I really like the automatic sliding hitch from Demco part # DM8550022 with the rail kit part # DM8551000 which is the best option but for a standard slider the Companion part # BWRVK3400 with the rail kit part # BWGNRK1108 would also be an awesome option.
    view full answer...
  • Recommended Auotslide Fifth Wheel Hitch for 2008 Ford F-250 Super Duty with 6-3/4 Foot Bed
    I do have a solution for you. You are correct that most sliding fifth wheel hitches are to be kept forward except while slowly making sharp turns. This is because you don't want the connection point of the trailer to be that far back in your truck bed, putting so much weight on your rear axle. The solution to this is an automatically sliding fifth wheel hitch like the Demco Hijacker. The Hijacker is available for below bed rails, # DM8550022, or above bed rails, # DM8550034. It works...
    view full answer...
  • Base Rails for 2003 Ford F-350 Super Duty and Old Hijacker FHW 24 5th Wheel Hitch
    We definitely have the rails you need to mount your Demco Hijacker FHW 24 in the bed of your 2003 Ford F-350 Super Duty, but I'm unsure of the base style you have, so you'll need to compare your base and choose from the following: - Above-Bed Base Rails # DM8552006-71 - Underbed Rails # DM8551000 - SL Series Rails, Parts # DM6012 and # DM8553003 If you aren't sure which is the correct rails please just shoot me a photo of the base connection and I'll be happy to clarify which one you...
    view full answer...
    Image 1 for
  • Underbed Fifth Wheel Slider Recommendation for 2016 Ford F-250 That Slides Automatically
    If you are looking for an underbed fifth wheel rail kit that allows the install of a Demco Hijacker Autoslide we have just what you need for your 2016 Ford F-250 without the factory rail kit. For that you would need the part # DM8551000 for the rail kit. And then for the 18k Hijacker to fit the rails (without needing an adapter), you would want the part # DM8550022. If you needed the 21k Hijacker you instead would want the part # DM8550037.
    view full answer...
  • Is Locking Adapter Plate Needed for Demco Hijacker Autoslide on 2006 Ford F-250
    The Demco Hijacker Autoslide Locking Plate # DM6095 referenced in your question works with just the Tri-Glide model of the Trailair Pin Boxes. It is required for the Tri-Glide design in particular because the 3 steel rods on this model act as rollers, letting the bottom jaw glide forward and back during towing. The locking plate is needed with the Demco Hijacker Autoslide # DM8550022 to prevent the king pin from rotating inside the trailer hitch. If your existing pin box is not the Tri...
    view full answer...
  • 5th Wheel Trailer Hitch and Install Kit Recommendations for a 2015 Ford F-250 Short Bed
    Since your 2015 Ford F-250 has the short bed I strongly recommend using a 5th wheel installation kit and hitch and not using an adapter in a gooseneck hitch. The reason is that will the short bed truck you will want as much clearance as you can get when turning so that the trailer and truck do not collide. Adapters do not offer much additional clearance. Since you like the clean look of the gooseneck I have an excellent solution for you. I recommend the B&W system using installation kit...
    view full answer...
  • Recommended Auto-Slide 5th Wheel Hitch for 2016 Silverado 1500 Double Cab
    The 2017 Jayco Eagle 29.5FBDS has a gross trailer weight rating of just under 10K. Page 333 of the online manual for your 2016 Silverado 1500 indicates a towing capacity for the double cab with regular bed that ranges across the engines types from a low of 11K up to 17.7K so the truck seems good to go. I still suggest checking your manual. I recommend a custom-fit 5th wheel base rail installation kit since this type reduces drilling and overall installation time. Demco offers USA-made...
    view full answer...
  • Below Bed Base Rails for 2002 Ford F-250 and Demco Hijacker Autoslide 5th Wheel Trailer Hitch
    You can absolutely use the 18,000 lb Demco Hijacker Autoslide with the underbed rails on your 2002 Ford F-250 crew cab. What you need are the following: - Underbed Rail and Installation Kit for Demco Hijacker # DM8551000 - Demco Hijacker Autoslide 5th Wheel Trailer Hitch with Slider - 18,000 lbs # DM8550022 As you mentioned, this is also compatible with the 21,000 lb version of the Hijacker # DM8550037. Additionally, if your '02 F-250 has the factory 7-way but you need a 5th wheel wiring...
    view full answer...
    Image 1 for
  • 5th Wheel Trailer Hitch that Slides Automatically for a 2012 Ford F-350 Short Bed
    I will be happy to help you out. For your 2012 Ford F-350, if it has the factory installed 5th wheel prep package with the 4 pucks in the bed I recommend the Demco HiJacker # DM8550038. This hitch will fit directly into the puck system. It offers 14 inches of travel and does slide automatically. I have linked a video review for you. If the truck does not have the factory prep package then you will also need an installation kit, # DM8551000, and you would use the HiJacker autoslide version...
    view full answer...
  • 5TH Wheel Rail Kits and Hitches For a 2016 Ford F-350 Without Factory Prep/Puck System
    You will have several options for mounting a 5th wheel hitch in your 2016 Ford F-350. First is the Curt Custom 5th Wheel Installation Kit for Ford # C16424-204. This system gives you rails that will mount inside your bed and accept either a Sliding Hitch # C16541 for a short bed or Fixed Hitch # C16130 for a long bed. This system does mean that you will have the rails that are always in your bed which can be a hassle if you do slide things in and out of you bed a lot. Next is the B&W...
    view full answer...
  • Demco Hijacker 4 Pin Underbed System Measurement
    For your 2014 Ford F-250 short bed, it sounds like you have the Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches # DM8551000. These holes will be 13-1/2 inches on center front to back and 29-5/8 inches on center side to side. I've attached a photo to assist. This is compatible with the Demco Hijacker Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs # DM8550022. If that isn't the measurement, then send me...
    view full answer...
    Image 1 for
  • Operation and Compatibility of Demco Autoslide 5th Wheel Hitch with Air Lift Rear Air Bag Kit
    The rack-and-pinion slider mechanism in the Demco Hijacker Autoslide 5th Wheel Trailer Hitch # DM8550022 does work in both forward and reverse directions. Once the pin box causes the hitch head to turn past about 15-degrees the autoslide mechanism engages and slides the head unit rearward for better turning clearance. In your 2016 Ford F-250 short bed without factory rail kit you can use Demco installation kit # DM8551000 and for a wiring harness part # DM8555002 which plugs right in at...
    view full answer...
  • Below-Bed Base Rails for 5th Wheel Trailer Hitch on 2014 Ford F-250, F-350 Super Duty
    The only rail Husky offers for their sliding hitches for your 2014 Ford F-250 or F-350 Super Duty is the Husky Custom Base Rails and Installation Kit # HT31408-686. These rails are above-bed rails. Reese, Demco, and B&W offer below-bed rails for their sliding 5th wheel trailer hitches for your F-250 or F-350. I recommend the Demco Hijacker Autoslide 5th Wheel Trailer Hitch with Slider # DM8550022 and the Underbed Rail and Installation kit for Demco Hijacker Underbed Mount Series # DM8551000....
    view full answer...
  • 5th Wheel Trailer Hitch and Install Kit for a 2008 Ford F-350 Short Bed and 2010 Keystone Cougar
    Since your 2008 Ford F-350 is a short bed I recommend going with a slider hitch so you will have more clearance between trailer and truck cab when making tight turns. The slider hitches that offer the most travel are the Demco HiJacker auto-sliders, # DM8550022 for below the bed rail kit # DM8551000, or # DM8550034 for above the bed rail kit # DM8552002-71. These hitches also have the benefit of sliding automatically. This means you won't have to get in an out of the truck repeatedly...
    view full answer...
  • Auto-Slide Fifth Wheel Hitch Recommendation for 2002 Ford F250 Short Bed
    Yes, that does provide enough information. From a quick online search, it shows that your 2008 Keystone Cougar 276RLS is well under 18K, for this, I recommend the Demco Hijacker Autoslide 5th Wheel Trailer Hitch. You have two options, my recommendation, is to install with the below bed rails, using hitch # DM8550022 and rail installation kit, # DM8551000. The benefit of the below bed kit is a rail-free design that allows for full access to truck bed when hitch is removed. Or the second...
    view full answer...
  • 5th Wheel Trailer Hitch and Install Kit for a 2014 Ford F-350 Short Bed
    I will be happy to help. Nowadays there are 2 types of short beds. There is the regular short bed that is usually 6 to 6-3/4 feet long depending on the truck. And there is the super short bed that is less than 6 feet long. I don't think that the super short bed was an option for the 2014 Ford F-350 so you likely have a 6-3/4 foot bed. There are 2 ways to tow a 5th wheel trailer with a short bed truck. First, you could use a slider hitch. A slider hitch allows the hitch and trailer to slide...
    view full answer...
  • Can Demco Autoslide 5th Wheel Hitch Fit 2011 F-250 With B&W Turnoverball Gooseneck Hitch
    I have two options for you, but you won't be able to use your Demco Autoslide with the B&W Underbed Installation Kit. You can't mount additional rails with the B&W hitch installed, and you can't use an adapter since it is unable to withstand the torque from the autoslide. The first option is to sell the Demco and get a B&W Companion # BWRVK3400-5W. The other option is to remove the B&W underbed hitch and install new rails to work with your Demco. You can choose above or below bed rails...
    view full answer...
  • Recommended 5th Wheel For 2010 Ford F-250 Super Duty Towing a 39 Foot 5th Wheel Trailer
    I can help you decide which 5th wheel is better for your 2010 Ford F-250 with a 6-3/4 bed. The Demco # DM6076P-UL-21K and the Reese # RP30084 are very comparable in weight capacity and height adjustments. If it were me I would go with the Demco # DM6076P-UL-21K, because of its slightly higher capacity and the quieter ride, due to the additional dampeners. You will want to determine the total loaded weight of your 39 foot trailer and make sure it doesn't exceed the weight of the hitch...
    view full answer...
  • Solution for Towing Both Gooseneck and 5th Wheel Trailers Using Hitch With Under Bed Mounting Rails
    In order to easily tow both 5th wheel and gooseneck trailers and to leave the bed free when the hitches are removed, you'll want to use a Demco Hijacker Autoslide that uses their UMS under bed rails. For a 21K capacity Hijacker Autoslide hitch, you'll want so use part # DM8550037 with the # DM8551000 rail kit. Once the 5th wheel hitch is removed, you would use the # DM5988 gooseneck hitch which is compatible with the UMS rails. This option provides a lot of convenience, as the hitch...
    view full answer...
  • 5TH Wheel Hitch Adapter for 2009 Ford f-350 OEM to Industry Standard Rails
    I believe the factory Ford 5th Wheel Prep didn't enter the market until 2011. So I wonder if someone installed the same OEM style system or did a different underbed mounting system. If you are not 100% sure check the measurements. For the Ford OEM Mount, Demco 5th Wheel Rail Adapter for Ford OEM 5th Wheel Towing # DM6175. This converts the OEM mount to the Industry Standard above bed rails. These holes will be 13" center front to back and 30" on center side to side. There will also be...
    view full answer...
  • Recommended Sliding Fifth Wheel Hitch For 2016 Ford F-250 With Short Bed
    There are a couple ways you can go for a towing setup. If you want full access of your 2016 F-250 truck bed when you are not towing I recommend an underbed rail system for your fifth wheel hitch like the Demco, part # DM8551000. I then recommend a sliding hitch like part # DM8550022. This hitch has 14-inches of front to back travel so you can make sharper turns. The great thing about this hitch is that you do not have to exit the truck when executing turns because this hitch automatically...
    view full answer...
  • Auto Slider Fifth Wheel Hitch for 2013 For F-250 Short Bed
    There are a lot of great options for fifth wheel hitches for your 2013 Ford F-250, but the Demco Hijacker # DM8550024 is for use with Ford F-250 models that have the OEM Prep Package. Since you do not have the OEM Prep Package, I recommend the Demco Hijacker Autoslide 5th Wheel Trailer Hitch # DM8550022 and the Underbed Rail and Installation Kit for Demco Hijacker # DM8551000. This is the same autoslider system with a 18,000 lbs gross trailer weight capacity, it just has a different base...
    view full answer...


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Do you have a question about this Fifth Wheel Installation Kit?


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Jeff D
Installed by:
Jeff D
Employee Joshua S
Video by:
Joshua S
Employee Zach D
Video by:
Zach D
Employee Jacob T
Video Edited:
Jacob T
Employee Dustin K
Video Edited:
Dustin K
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Hannah L
Updated by:
Hannah L
Employee Kristina F
Updated by:
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Employee Justice A
Updated by:
Justice A
Employee Chelsea B
Written by:
Chelsea B
Employee Brent H
Test Fit:
Brent H

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