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  1. Fifth Wheel Hitch
  2. Demco
  3. Sliding Fifth Wheel
  4. Aftermarket Below Bed Rails
  5. 18000 lbs GTW
  6. Premium - Single-Hook Jaw
Demco Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs

Demco Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs

Item # DM8550022
Our Price: $1,910.00
You Save: $601.09
Fifth Wheel Hitch
Shipping Weight: 300 lbs
In Stock
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This hitch slides automatically as you drive to give you 14" of additional clearance for tight turns. A wraparound jaw provides a smooth ride and a locking bar offers added security. Hitch removes easily for full bed access. 1-636-245-6107 to order Demco fifth wheel hitch part number DM8550022 or order online at Free expert support on all Demco products. Great prices and Fastest Shipping for Demco Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs. Fifth Wheel Hitch reviews from real customers.
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Demco Fifth Wheel Hitch - DM8550022

  • Sliding Fifth Wheel
  • Demco
  • Aftermarket Below Bed Rails
  • 18000 lbs GTW
  • Premium - Single-Hook Jaw
  • Double Pivot
  • 4500 lbs Vertical Load
  • 14 Inch Fore/Aft Travel
  • 15-1/2 - 18-1/4 Inch Tall

This hitch slides automatically as you drive to give you 14" of additional clearance for tight turns. A wraparound jaw provides a smooth ride and a locking bar offers added security. Hitch removes easily for full bed access.


  • 5th-Wheel hitch mounts in your short-bed truck bed so you can tow your 5th-wheel trailer
  • Automatic slider provides clearance required for your short-bed pickup to turn safely at slow speeds
    • No more getting into and out of the truck to operate a manual slider
    • Head slides toward the tailgate when you turn and back toward the cab when you straighten out
    • Rack-and-pinion gears create smooth, controlled, automatic motion
  • Rotating hitch head turns up to 90 degrees with your trailer
    • Rotation creates the force that propels the automatic slider
    • Built-in brackets stabilize your pin box so the king pin won't rotate in the hitch - no need for a separate capture plate for standard pin boxes
  • Rail-free design allows for full access to truck bed when hitch is removed
  • Wraparound, single-piece jaw provides a secure connection
    • 360-Degree jaw-to-king-pin contact
    • Less rattle and more security than slide-bar jaws
  • 3/4" Thick, solid steel locking bar reinforces the connection of your coupled trailer
    • Automatically locks into place when the jaw closes
  • Double-pivot hitch head eases hookup and helps to limit chucking
    • Pivots front to back and side to side
  • 3 Height settings to fit your application
  • Cushioning polyurethane dampeners help reduce noise and absorb road shock
  • Spring-loaded handle with comfort grip allows for simple coupling
    • Tethered safety pin lets you secure the handle in the open or the closed position
  • Sturdy steel construction with rust-resistant black powder coat finish
  • Custom Demco underbed mounting kit (sold separately) required for installation
  • Made in the USA


  • Designed for use on 6-1/2' truck beds
  • Fits standard pin boxes 12" - 14" wide
    • Locking plates (sold separately) are required for use with Glide Ride, Mor Ryde, Trailair Tri Glide, Trailair Flexair, Rota Flex, and 5th Airborne pin boxes
  • Gross towing weight: 18,000 lbs
  • Vertical load limit: 4,500 lbs
  • Travel: 14" front to back
  • Hitch height settings: 15-1/2", 16-3/4", and 18-1/4"
  • Hitch base dimensions: 37" long x 32" wide
  • 5-Year limited warranty

Note: This fifth-wheel trailer hitch is not compatible with Sidewinder or Revolution king pins. Do not use any device that changes the pivot point of your trailer's king pin with this hitch.

Automatic Slider Makes Cornering Easy

Most often used on trucks with 6-1/2' beds, a slider helps to eliminate clearance problems during slow-speed turns. When you are towing a fifth-wheel trailer, your hitch must be situated on the cab side of your truck's rear axle. However, at slow speeds you can use a slider to slide the fifth-wheel hitch (and the trailer) toward your truck's tailgate and past the rear axle, creating enough space between the cab of your truck and the trailer to permit less-restricted turning.

Normally, you'd have to get out of your truck and pull a lever to release the slider before every turn, but what if there was an automatic system? Imagine having 14" of extra clearance while towing your fifth-wheel trailer. Now imagine having this without needing get out of the truck to move your slider. The Demco Autoslide makes this fantasy a reality. The Autoslide automatically glides back smoothly when you make a sharp turn so you can maneuver effortlessly around tight corners within campsites and parking lots.

Demco Hijacker Autoslide

The base of the Autoslide has a built-in rack-and-pinion gear system that operates automatically. As your truck turns, the pinion in the base also turns. This activates the rack gear, which causes the rotational force of the truck to be converted into the linear sliding action of the hitch. So, when your truck makes a sharp, slow-speed turn, the gears inside the Autoslide force the hitch head to slide down toward your truck's tailgate in a smooth, controlled motion. This way, any time that your truck turns more than 10 to 15 degrees, the Autoslide will ensure that there is enough clearance for your trailer to complete the turn as well, and it will do so without any jerking or binding.

In order for the rack-and-pinion assembly to function as designed, the pin box must be stabilized on the hitch head. Normally in a fifth-wheel hitch, the king pin moves inside of the hitch head so that the trailer can turn. With the Autoslide, the king pin remains fixed inside of the jaws of the hitch and it is the hitch head itself that turns. This is thanks to the capture brackets on the sides of the head that brace the pin box from both sides to hold it in place on top of the hitch head. This is done to ensure that there is enough resistance within the hitch when your truck turns to properly activate the rack-and-pinion gear mechanism.

Demco Hijacker Autoslide capture bracket

To stabilize your pin box on the hitch head, simply push the capture brackets up against your pin box once the trailer is coupled and tighten the outer bolts and the inner jam nuts. The Autoslide head and brackets will fit standard pin boxes that are between 12" and 14" wide. If you have a Glide Ride, Mor Ryde, Trailair Tri Glide, or 5th Airborne pin box, you must install a special locking plate (sold separately) as well.

When you straighten your rig out again and your trailer moves back in line, the hitch head will rotate back to center and slide back toward the cab into the straight towing position.

Secure Wraparound Jaw with Locking Bar

Demco Hijacker Autoslide wraparound jaw and locking bar

The single-piece, strong wraparound jaw completely surrounds your trailer's king pin for 360 degrees of contact. This wraparound jaw provides a more secure connection than standard 2-piece jaws that close in on the king pin from the sides. The increased jaw-to-king-pin contact on the Autoslide offers tighter tolerances around the king pin, which minimizes both rattle and chucking, for a smooth, quiet ride.

A 3/4" solid steel locking bar spans the area in front of the jaw. This bar provides an added barrier of protection against accidental disconnection so you can have peace of mind that your trailer is secure. The locking bar is attached to the jaw and to the spring-loaded handle. The bar automatically locks when the jaw closes around your king pin.

Double-Pivot, Cushioned Hitch Head

The double pivoting, cushioned head improves your towing experience dramatically by helping to reduce jarring and unwanted noise. Built-in pins allow the hitch head to pivot back and forth and side to side. And hooking up is easy because the hitch head will automatically pivot to the proper angle when it comes into contact with your pin box.

Three polyurethane dampeners help to cushion the movement from the pivoting head and to reduce towing noise. Two of these dampeners are built into the head assembly to cushion the head's side-to-side pivoting. The third dampener cushions the back-and-forth motion and must be installed in the hitch prior to use. Installation of this third dampener is easy - simply press the dampener up into the pre-drilled hole underneath the hitch head.

Easy Installation

The Autoslide hitch is specially designed to fit a Demco UMS custom underbed mounting kit (sold separately). The hitch comes pre-assembled for an easy installation. All you have to do is bolt on the side plates and attach the head to the hitch base.

The side plates have 2 functions. They contain the feet that fit into the receivers in your truck bed, and they allow you to raise or lower the hitch head to better match your pin box height. After you choose your desired height setting, simply bolt the side plates to the hitch base with the included hardware. Then lower the hitch into the 4 UMS receivers in your truck bed. Turn the handles to lock the feet into the receivers and secure the handles with the included safety pins. The hitch can be removed to give you full truck bed access. Simply remove the safety pins, turn the handles to unlock the feet, and lift the hitch out of the receivers.

Clearance Formula for Short Bed Trucks

Use the formula below to ensure there will be enough space between your truck cab and trailer when executing a 90-degree turn.

(A+B) - C = Clearance

A = Distance from the center of fifth-wheel hitch jaw to truck cab

B = Length of Travel (14")

C = Width of trailer divided by 2 (to get half)

For example: If the distance from the center of the hitch to the cab is 36", 36" + 22" = 58". If your fifth-wheel trailer is 102" wide, take half (51"), then plug in: 58" - 51" = 7" of clearance.

Note: At least 4 inches of clearance is recommended to safely execute a 90-degree turn.

6077 Demco Hijacker Head Assembly for Auto Slide 5th Wheel Trailer Hitch - 18,000 lbs

6004 Demco Hijacker Adapter Plates for Underbox Mount 5th Wheel Trailer Hitch

Installation Details DM8550022 Installation instructionsAlternate Instructions DM8550022 Installation instructions

Customer Satisfaction Score:

Customer Reviews

Demco Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Underbed - 18,000 lbs - DM8550022

Average Customer Rating:  4.7 out of 5 stars   (540 Customer Reviews)

This hitch slides automatically as you drive to give you 14" of additional clearance for tight turns. A wraparound jaw provides a smooth ride and a locking bar offers added security. Hitch removes easily for full bed access.


This was the best solution for my Dodge RAM 2500 towing my Alliance 340RL 38' 5th Wheel. My son helped me install the rails under the bed and now it is very easy to remove the hitch when I am not using it. It is very strong and I highly recommend this for anyone with a short bed truck.


When you use google chrome it does not move you to the next page to custom fit.
So it just tells you your truck shows you the product and I order 6k worth of items without putting in the custom specs that you don't know to hit. Somehow with the info I put in my two other products work but this one doesn't and I have to pay for shipping to this to fix it. Wish if you ordered 6k worth of Items they would be a little more understanding that their site does not walk you what needs to be done and help you fix the problem without charging you more. Prep and Puck systems are two different things now I know.


The star rating is a 5, Review for etrailer is the date promised on delivery was right on, delivered direct to installer and the Product Demco slide hitch is all that Demco claims it does.


this hitch works as advertised.was a great suggestion. very heavy duty and well constructed! never have to leave the cab to release the slide just drive! custom fit under bed rails worked perfect on my 2016 f drilling frame rails. installed it myself. i am a.s.e. master auto / truck mechanic.every one at e trailer was very help full when i called with questions.they did as they said they would.was so pleased with every thing.i purchased a hitch for the front of the same to works as as it should also. thanks!

good happy with the whole set up.had a small issue that demco remedied swiftly.only other thing is the finish does not seam to is covered when not in use and it chips and rust,s easily
Buddy R - 03/24/2019


2003 Chevrolet Silverado 2500HD 4x4 extended bed Duramax


The demco hitch was easy to install.
up well with 0 issues over the past year.


Overall I love the auto slider mount and it works as advertised. Easy to hook up and unhook. Just have to make sure your truck is in a straight line with the RV when unhooking because you don’t want to leave this thing turned or it can be very hard to hook back up. I learned this the hard way. Turning it by hand does not work either.
The plastic inserts to cover the holes when the mount is removed don’t work because the holes are too shallow on my F250,, but that makes no difference to me because the mount is way to heavy to remove anyway. The only thing that does bother me is the rust. I have used a wire brush and rustoleum paint on several spots now. Perhaps better rust proofing would be something the company could look into for future mounts. I mounted mine in a 2017 F250 with the 6.5’ bed and added a toolbox in front of it. Had to go with the in-bed box because my rv would have hit one of the boxes that sits on top of the bed. When backing up and turning my RV (Grand Design Reflection 307MKS) misses the cab by a good 3 inches. Installation of the mount rails that go under the bed was time consuming, not much room to use a wrench under there so each bolt took a while to tighten into place. The slider is big and heavy so it was a chore getting it dropped into the holes, I got 3 big guys to help out with that part. If I had to do it again I would not have done this install myself, I would have found a shop to do it prior to buying the RV. But I already bought the RV and could not wait for a shop to get it done.


Love this hitch! Works great in 2019 F250 CC w/short bed, I can turn 90 degrees and still miss cab of truck. No problems latching and unlatching as long as everything is fairly level. I installed hitch with under bed kit by myself, wasn't too bad. I've had hitch for a year now with no problems. I would recommend Demco Hijacker Autoslide hitch.


The Demco hijacker 18 K I think is the best hedge out there by far three different height settings and the auto slider part of it is awesome haven’t had an issue at all
Andy - 03/15/2022


Unit is built heavy duty. Installation was pretty straight forward. Towed fifth wheel from West Virginia to Pennsylvania with no issues.


So pleased with this hitch! Works great on my 2015 F250 short bed. Works well with my retractable tonneau cover, fits under perfectly on the low adjustment points. If you have a short bed this hitch is the one to have.

etrailer customer service was awesome as usual!


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.


Really like our Demco hitch, had some issues with chunking when turning, took to Demco in Iowa when passing through and they completely refurbished and readjusted to bring up to their new specs. Would deffenately buy another Demco Autoslider!


The Demco Autoslide is the only way to go for a 5th wheel hitch for a short bed truck. The extra 14" of travel is great. Left me truck almost 90 degrees. It was even easy to install by yourself with a lot help from another person.



Thomas S - 02/07/2019


Hitch works perfectly. The auto slide is awesome! Very well built. Very heavy. Not something you want to be taking in and out of your bed all the time. My only complaint is that you have to be pretty straight when you hook or unhook the camper.


Very good fifth wheel. No problems works good. have used it alot since installed cannot hook up to trail air with out plate being installed on trailer hitch


Seems to be very well made and high quality. Definitely takes two to lift up and into position. Minimal work required to get this slider running as it’s nearly all preassembled from the factory. Just needs the locking pin rails installed. I installed mine on the medium height setting and it has worked out very well so far with my 2020 F-250 shortbed.


Smooth operation and being a auto slider you just hook up and don’t have to worry about sending the trailer through the cab of your short bed truck because you forgot to unlock your slider. It’s pretty awesome.


No problems


Love it. I like that it comes out and you get your bed back. If I had one thing to say bad on it is that when you back up to it you have to be lined up straight with it. You can't come in on an angle. But it's not the end of the world. It's great you don't have to get out in the rain to slide it back for the sharp turns.


I'm very happy with the product. Less so with the instructions. Wished they could have a little more explanation to them about the assemble of the hitch itself. The undermount was fairly easy and would suggest it to anyone with a 17-19 Superduty.


Arrived quickly. Heavy duty hitch. Folks at E-trailer kept me updated and were polite and professional when I spoke with them on the phone. Installing myself so going slow but I have the time.



This hitch has been awesome.
It works perfectly all the time. My only gripe would be that the head doesn’t fall down automatically. I have to get out of the truck to tilt it down when connecting to my trailer. Other than that, I’m very satisfied with the design and operation of the hitch.

Thank You


Hitch works great so far, installed in a 6-1/2 foot bed pulling a 39 ft 5th wheel.

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