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Demco Hijacker Autoslide 5th Wheel Trailer Hitch Installation - 2021 GMC Sierra 3500

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How to Install the Demco Hijacker Autoslide 5th Wheel Trailer Hitch on a 2021 GMC Sierra 3500


What is going on everybody Adam here with etrailer. Today on our 2021 GMC Sierra 3500, we're gonna be taking a look at the Demco Hijacker auto sliding fifth wheel hitch kit, or your OEM prep package. This system is gonna be for you if you have the OEM puck system and you have a short bed. Basically what happens is, with these short beds, as you start turning, a lot of the ones you're gonna have to like manually release so you can slide it back. So you're not gonna have any damage happening to the cab of your truck. With this one, as it starts to rotate, it's gonna slide back automatically to prevent any contact from happening.

We're gonna get about 14 inches of slide with our fifth wheel head, and it is gonna rotate up to 90 degrees with our trailer. To get a closer look at the jaws, what we wanna do is just take this little pin out here, gonna pull this lever and it's gonna lock in to place. Out like that, and then, just gonna take this out real quick. Then we get a closer look at the jaws. So this is gonna be a one piece and it is going to cover 360 degrees around your king pin.

So that's gonna prevent any type of rattling. So as you start backing up to your fifth wheel, it'll slide in like that. And then click into place. Then you can replace the pin. Another thing I like about this head is, it is going to rotate front to back but also side to side.

A lot of the times it's not ideal conditions. We're not always gonna be perfectly level, and it's just gonna be a little off. So this is gonna give you a little bit less of a headache whenever you're trying to hook up. And also whenever you're driving, it's gonna prevent that chucking that you'll feel whenever you're going down the road. A lot of fifth wheel hitches are a little noisy back behind you whenever you're going down the road.

With this one, a lot of the movement that you'll be feeling, is kind of that side to side action. And we do have some polyurethane dampeners. So they're gonna last a long time, and just keep that noise to a minimum. There's only one adjustment that we need to take into consideration. Right now, we're using the middle holes here. There are some measurements you need to take to figure out which one's gonna be best for your rig, meaning your truck and your trailer. One thing I noticed is using the middle or the bottom, you are definitely able to get a on top of the rail tonneau cover to cover up your fifth wheel and hide it from the elements. If you do have to use these taller ones here, it's gonna sit a little bit higher up than the sides of your bed. To sum it all up, if you have a short bed pickup, I would definitely recommend grabbing a sliding fifth wheel hitch. We have a lot of them here. I really enjoyed the Hijacker. It was a pretty easy install. Whether you have an OEM puck system or not, we have a lot of different rails that you can grab here at etrailer. So you can get this Hijacker system onto your truck. If you do have an OEM puck system, you can go ahead and stick around. We're about to go ahead and install the adapter rails for that puck system, along with the rest of the fifth wheel. First thing we wanna do is remove our little covers for our puck system. These pop right out. Put these somewhere where you won't lose them. These are designed to drop right into your OEM puck system, but we we're having a little bit of issues with it lining up. If you do have that issue, what we did is you can just loosen some of these bolts to loosen up this bracket. It gives you a little bit more wiggle room. And then, it dropped into place. And now that everything is loose, it's a good idea to kind of get everything to see if it's gonna turn. And if it is, then we don't have to remove anything. If you aren't able to turn, there is a couple of different washers that will be accessible with this bracket taken off, that you might have to remove to get it to lock into place. Once everything's in place, you can tighten everything down. I'm using a 14 millimeter socket. Now that we have our base in place and locked down, grab a couple of set of hands to help you get this heavy slider up and onto your bed. And to get it to the right orientation, we're gonna have two bolts and that's gonna be facing towards the back. And then the one facing towards the front, is just gonna have one single bolt in the middle. To make it easier to put the side brackets on, it's really nice to have a six by six on the front and back to kind of lift it up to where these holes are gonna line up. And now we get to determine which holes we're going to use. We're gonna use the middle ones, but what you need to do is get your trailer level and then measure from the ground to your king pin, and then measure from the ground to the top of your tailgate. Take those two numbers and the difference. Look in your instructions to figure out which one it matches up with. Ours matches up with the middle. So we're gonna use the middle in lining up with these top holes. Now you wanna go ahead and take your hardware. We're gonna put these through the holes and take this big nylon lock nut. And reach in and put it on the back. And then in our instructions, we are gonna have some torque settings. So you can go ahead and torque it down nice and tight. With an extra set of hands, we can lift this up. Now we can kind of start to line it up to where we need it, and drop it into these little slots. And if you haven't already, go ahead and take your pins. I'm gonna line this up. Bracket will come in through there. Have a little clip to go on the end. And it's the same exact thing for all four sides. Now that the hitch is in place, what we wanna do is set up our outrigger bar. So what we did is we took some of the hardware before, and we ran a bolt through to kind of get rid of some of that powder coat that made it to the threads. So it's gonna be a little bit easier to do this. So what we wanna do, is we're gonna stick it through, put this nut on, put it down there, and then now that there's not a whole lot of powder coat in those threads, it's pretty easy to go through. There is a nice pad on the bottom. So what we wanna do is pretty much get it all the way through the bracket, but not sticking out too far. It's kinda like that. And then we'll take this, go all the way up, take the other one, go all the way down, and then make some minor adjustments to where it's just kind of supporting this right here. And then we can tighten it down with a three quarter inch socket. Before we install our head, you wanna take our dampener and there's gonna be one little hole in the bottom. All you gotta do is just line it up, press it down, and that's it. To get our head in place, what we wanna do is pull this pin here and take out the pivot pin. Just like that, set it to the side. And we can go ahead and set this down, line it up, and then we can put this pin back in place, going all the way through, and then replace our pin. Now we wanna install the handle. So what we wanna do, is just slide it on, and there's multiple holes. So we don't want to have it up like this. It might run into our camper that we're hauling. So I'm just gonna have it like this. And then we'll get a bolt that goes through there, and a nylon lock nut to go on the other end. And you can go ahead and tighten it down. Most likely, you're gonna have to adjust these here just to fit the pin plate on your pin box. And it's gonna accept from 12 inches all the way up to 14 inches of your standard pin boxes. Now's a good time to go ahead and back up to your fifth wheel, get it all hooked up and see if it is at the right height. If it's not, we can make our adjustments on our brackets here. And that'll do it for a look at the Demco Hijacker sliding fifth wheel kit for your 2021 Sierra 3500 with the OEM puck system..


Questions and Comments about this Video

Info for these parts were:

Employee Jeff D
Installed by:
Jeff D
Employee Dustin K
Video Edited:
Dustin K
Employee Chris R
Video by:
Chris R
Employee Adam E
Test Fit:
Adam E

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