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

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

Item # DM8551008
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Fifth Wheel Installation Kit

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Demco Custom - DM8551008
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Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Hijacker Underbed Mount Series (UMS) fifth-wheel and gooseneck hitches. Call 800-298-1624 to order Demco fifth wheel installation kit part number DM8551008 or order online at etrailer.com. Free expert support on all Demco products. Guaranteed Lowest Price and Fastest Shipping for Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches. Fifth Wheel Installation Kit reviews from real customers.
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  • Q & A (18)
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Demco Fifth Wheel Installation Kit - DM8551008

  • Below the Bed
  • Demco
  • Custom

Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Hijacker Underbed Mount Series (UMS) fifth-wheel and gooseneck hitches.


Features:

  • Installation kit is designed for use with Demco Hijacker 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
    • Brackets mount to the outside of your truck's frame rails - drilling is required
    • 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 Hijacker Underbed Mount Series (UMS) 5th-wheel and gooseneck trailer hitches
  • 5-Year limited warranty


8551008 Demco High Jacker UMS Under Bed Rail Frame Bracket Kit

Replaces Demco DM8551007

Installation Details DM8551008 Installation instructions

This Product Fits The Following Vehicles





Customer Reviews

Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches - DM8551008

Average Customer Rating:  5.0 out of 5 stars   (1 Customer Reviews)

Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Hijacker Underbed Mount Series (UMS) fifth-wheel and gooseneck hitches.

- DM8551008
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Ask the Experts about this Demco Fifth Wheel Installation Kit

  • Recommended Airbags for a 2017 GMC Sierra 1500 with 5th Wheel Hitch
    There are airbags kits that will interfere with the frame brackets for a 5th wheel hitch and there are airbag kits that will not interfere with the frame brackets for a 5th wheel hitch. This is all going to depend on where the frame brackets for the 5th wheel hitch mount in relation to where the frame brackets for the airbags mount. The only underbed mounting kit we have for your 2017 GMC Sierra 1500 with the 5-1/2' bed is the Underbed Rail and Installation Kit for Demco Hijacker UMS...
    view full answer...
  • 5TH Wheel Trailer Hitch For Lippert Turning Point On 2012 Chevrolet Silverado 1500 5-1/2' Bed
    I do have an option for you as with the Lippert Turning Point Pin Box you cannot use a 5th wheel hitch like the B&W Companion 5th Wheel Trailer Hitch # BWRVK3400-5W. This is due to the single attachment point of this particular style hitch. If you wish to keep the same clean bed style as the B&W with your short bed(5-1/2') 2012 Chevrolet Silverado 1500 you will need the Underbed Rail and Installation Kit # DM8551008. This will allow you to use their Demco Hijacker UMS Series Gooseneck...
    view full answer...
  • Recommended Underbed Rail System for 5th Wheel Hitch on 2017 Chevy Silverado 1500 Elite Series
    There is not a Reese Underbed rail system available for your 2017 Chevy Silverado 1500. If you want an underbed rail system for a clean bed when not towing a 5th wheel trailer, I recommend the Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches # DM8551008 which is compatible with the Demco Hijacker Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs # DM8550022 or 21,000 lbs # DM8550037. If you prefer a manual...
    view full answer...
  • Slider Hitch Recommendation for 2007 GMC Sierra 1500 New Body
    Since your truck bed is shorter than 6 feet long there's only one slider hitch that will have enough clearance to allow you to make tight turns and that's the Demco Hijacker Autoslide part # DM8550040 which slides back 22-1/2 inches which is about twice as much as other options. Also since this hitch slides back automatically you wouldn't have to worry about getting out and manually operating the slider either. Then to install it in the bed of your 2007 GMC Sierra 1500 you'd need the...
    view full answer...
  • Best 5th Wheel Trailer Hitch for Turning Clearance for a 2015 GMC Sierra 1500 Short Bed
    There are a couple of ways you can get increased clearance between the truck cab and the 5th wheel trailer when making tight turns. In your picture it doesn't look like you have a hitch yet so the most cost effective solution is going to be a sliding 5th wheel hitch. I recommend a Demco HiJacker auto-sliding hitch. That way you don't have to get in and out of the truck to operate the sliding mechanism. I assume that your 2015 GMC Sierra 1500 is a short bed but it is the really short...
    view full answer...
    Image 1 for
  • Recommended 5th Wheel Hitch & Underbed Kit for 2015 Chevrolet Silverado 1500 5-1/2-Foot Bed
    Usually a very short bed truck like your 5-1/2-foot-bed 2015 Chevrolet Silverado 1500 does require a 5th wheel replacement pin box, a Reese Sidewinder or Revolution, in order to have enough turning clearance for tight maneuvers. Sidewinders provide a substantial 22-inches of additional clearance. But you do have an option in the Demco under-bed mounted slider hitch # DM8550041 and mounting kit # DM8551008. Most slider hitches provide 10- to 14-inches of additional turning clearance...
    view full answer...
  • Recommended Best 5th Wheel Hitch for 2017 GMC Sierra 1500 5-1/2 Foot Bed
    The best hitch for your 2017 GMC 1500 Denali is really based on preferences. My recommendation for the best is the Demco Hijacker Autoslide # DM8550041 with the Underbed rail kit # DM8551008 because it gives you a completely clean bed when not in use and then provides you with a hitch that has 22-1/2 inches of travel that automatically moves as needed to give you the turning clearance needed. I've attached a video of this hitch installed in a 2017 Chevy 1500 to assist. The biggest benefit...
    view full answer...
    Image 1 for
  • How to Tow a 5th Wheel Trailer with a 2017 Chevrolet Silverado 1500 that has a 5-1/2 Foot Bed
    I have attached the formula that is used to determine turning clearance with a 5th wheel trailer for you below. In order to give you the exact measurement you are looking for we would need to know the distance from center of fifth wheel hitch jaw to the truck cab. However, I can already tell you that you will need to use either a rotating pin box or sliding 5th wheel hitch with at least 22-1/2" of travel in order to execute a 90 degree turn with your 2017 Chevrolet Silverado 1500 because...
    view full answer...
  • Recommended Fifth Wheel Options For 2007 GMC Sierra Crew Cab With Short Bed
    With the length of the truck bed in your 2007 Sierra, a standard sliding fifth wheel hitch will not provide enough clearance for you to execute turns when towing. There are two ways you can go at this. I recommend going with the Demco Hijacker Autoslide, part # DM8550040. This hitch gives you 22-1/2 inches of additional clearance so you can make those tight turns. For above-bed rails you can use part # DM8552013-71. If you want full use of your truck bed when you are not towing I...
    view full answer...
  • Recommended Under Bed 5th Wheel Base Rails for 2018 GMC Sierra 1500 Short Bed
    I have great news! For your 2018 GMC Sierra 1500, I highly recommend going with the Underbed Rail and Installation Kit # DM8551008, which is compatible with the excellent Demco Hijacker Autoslide # DM8550022. The custom under bed rail kit is confirmed to fit your truck and allows for uninhibited use of the bed when the hitch is removed. The Demco Hijacker features a towing capacity of 18,000 pounds and will slide automatically as you drive to give you 14 inches of additional clearance...
    view full answer...
  • Recommended Underbed 5th Wheel Hitch Mount for 2017 GMC 1500 with 6-1/2 Foot Bed
    There is not a Reese Elite Puck System Underbed kit abailable for your 2017 GMC Sierra 1500. Your best option is to use the B&W Companion 5th Wheel Trailer Hitch w/ Slider - Dual Jaw - 20,000 lbs # BWRVK3400-5W along with the B&W Turnoverball Underbed Gooseneck Trailer Hitch w/ Custom Installation Kit - 30,000 lbs # BWGNRK1057. This combination will give you a gooseneck hitch, a clean bed, and a sliding 5th wheel hitch. If you want an automatically sliding hitch, then you will give...
    view full answer...
  • Under Bed 5th Wheel Trailer Hitch Installation Kit for a 2015 GMC Sierra 1500 Short Bed
    Reese does not offer an under bed 5th wheel installation kit for your 2015 GMC Sierra 1500. The least expensive under bed and hitch option is going to be from Demco using installation kit # DM8551008 and HiJacker hitch # DM8550022 for a short bed. Another option is to use Curt gooseneck hitch # C615-632 and X5 adapter # C16210. The X5 adapter fits in the gooseneck ball hole for this gooseneck hitch and provides standard rails to mount a hitch. If you do not already have a hitch you can...
    view full answer...
  • Can Demco 18K Hijacker Autoslide 5th Wheel Hitch Be Used on 2018 GMC Sierra with 5-1/2 Foot Bed
    I do have a couple of great options for you, however the Demco Hijacker Autoslide 5th Wheel Hitch # DM8550034 that you referenced features 14" of front to back travel on the slider, which almost certainly isn't enough to provide cab clearance during sharp turns on your 2018 GMC Sierra 1500 that has the 5-1/2 foot bed. If you like the idea of an automatic sliding hitch, the much better option will be with the Demco Hijacker Autoslide # DM8550041, which actually provides 22-1/2" of front...
    view full answer...
  • Can B&W Companion be Used to 5th Wheel Tow with 15 Chevy Silervado 1500 with 5-1/2 Bed
    The Custom Underbed Installation Kit # BWGNRK1057-5W will fit your 2015 Chevy Silverado 1500 with the 5-1/2' bed and while you can technically use the Companion Slider # BWRVK3400-5W, it (and any other standard slider hitch) will not provide enough turning clearance for your trailer and 5th wheel trailer. Since you have a 5-1/2' bed you need something that will give you at least 22" of turning clearance and we do have a few options for you. The first option is to use the Demco 13K Autoslider...
    view full answer...
  • 5th Wheel Trailer Hitch and Install Kit Recommendations for a 2015 GMC Sierra 1500 5-1/2 Foot Bed
    Yes, you can install a 5th wheel trailer in your 2015 GMC Sierra 1500 with 5-1/2 foot bed. But because the bed is so short you will need a special hitch in order to have clearance between the trailer and the truck cab when making turns while towing. For that I recommend the new Demco auto-sliding 5th wheel hitch # DM8550041. This hitch has an astonishing 22-1/2 inches of travel for the clearance you will need. It is rated for 13,000 pounds which is likely more than what the truck can...
    view full answer...
  • Sliding 5th Wheel Hitches With Underbed Rails Compatible With 2016 and 2017 Chevy And Ram Short Beds
    There are definitely options for underbed rails on 2016 and 2017 Chevy and Dodge short bed trucks. For the Chevy 6-1/2 foot bed, I recommend the Custom Underbed Installation Kit for B&W Companion 5th Wheel Trailer Hitches # BWGNRK1057-5W along with the B&W Companion 5th Wheel Trailer Hitch w/ Slider - Dual Jaw - 20,000 lbs # BWRVK3400-5W. This system allows you to use a 5th wheel hitch or a gooseneck hitch and will give you a clean bed when not in use. Another option is to use the...
    view full answer...
  • 5th Wheel Hitch Recommendation for a 2015 Chevy Silverado 1500 with 5-1/2' Bed
    Since you have a 5-1/2' bed on your 2015 Chevy Silverado 1500 the only sliding 5th wheel hitch that has enough travel (22-1/2") to give you proper cab clearance is the Demco 13K Hijacker Autoslide 5th wheel hitch; unfortunately the B&W Patriot # BWRVK3270 doesn't have enough clearance. For standard base rails you need the part # DM8550040 with rails # DM8552027-71 but if you're wanting a system that gives you a clean bed when the hitch is removed you need the part # DM8550041 with...
    view full answer...
  • Recommended 5th Wheel Trailer Hitch for 2015 Chevy Silverado and Revolution King Pin
    The only under bed system available for your 2015 Chevrolet Silverado 1500 is the Demco Hijacker # DM8550041 along with the Underbed Rail Kit # DM8551008. This particular hitch is not compatible with the Revolution king pin on your trailer. I instead recommend looking at the Reese Select Plus 5th Wheel Trailer Hitch # RP30928, along with the Quick-Install Custom Base Rails # RP50064-58. This is an excellent hitch that features a forged, single-piece self-latching jaw that will provide...
    view full answer...

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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Joshua S
Video Edited:
Joshua S
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Updated by:
Kristina F
Employee Amanda M
Written by:
Amanda M
Employee Brent H
Test Fit:
Brent H

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