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Demco Hijacker Underbed Rail and Kit Installation - 2015 Chevrolet Silverado 2500

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How to Install the Demco Hijacker Underbed Rail and Kit on a 2015 Chevrolet Silverado 2500


Today on this 2015 Chevrolet Silverado 2500, we're going to review and install the Underbed Rail Installation Kit for a Demco Hijacker UMS fifth wheel and gooseneck trailer hitches, part number DM8551010.This is what the rails look like when they're installed under the truck. You can see we got the two cross rails going from left to right, and they sit on the frame below the bed. Let's check out on the bed of a truck, and we have our hitch already in place. It's kind of integral for installation by the way, but we take a look down here. All we have is four holes drilled in the bed, two inch diameter holes, very easy to do, and your hitch sits right in there. The big plus about this setup is, is that when you take your hitch out, you have full access to your bed.Now these base rails will fit a variety of Demco products, including all the auto slide pitches they offer.

Let's do a quick look at the frame brackets here on the side of the frame, we're actually looking on the driver's side. You notice the four big bolts that hold it in place onto your frame, those are all no drill applications, so you have to worry about drilling into your frame at all.Now comparing this to other fifth wheel hitches and rail systems out there, how the rails sit on top of the bed, you can still use your truck, but you got to drag your stuff over the rails. With this setup, I think it's worth the extra effort to put into it to install this one so you have free access to your bed. And basically all you have is four holes, but that's it that goes to your hitch, and then you have full access to your bed.Now I'll go ahead and show you how we install it. First part of our install is we need to mark the holes that need to be drilled in the bed of a truck.

There we're two sets of instructions for the measurements, depending on the length of the bed of your truck, so double check to make sure you have the correct length bed for your measurements. Now when you're do your measurements, they're all based on the edge of the bed right here. Don't touch the tailgate. Start from this point and measure up. So eventually we'll have four holes drilled into the bed of the truck here.

After I mark my holes, I have to drill them out with a very small pilot bit. Do all four like that and I'll double check my measurements.Once you're happy with your measurements, I'm going to drill out with my quarter inch for a pilot hole and that will work for my hole saw. Now follow up for a two inch hole saw. One down three to go. Once you have your holes drilled out, it's a good idea to spray something there, like spray paint or some kind of clear coat to help protect the metal when you're done.Now we can start doing our work underneath the truck, which means get the spare fair tire out of our way, and then we have to get access to our heat shield right here.

We need to cut out a couple of sections here and here to make room for our rails. Depending on what you cut the heat shield with, you may want to loosen up the exhaust too. That means removing rubber hangers. We'll let it come down just a little bit, but still support it, to give us more working room as well.Spray it down with some lubricant. I like using silicone, and we'll pry off the hanger. And we'll work our way up forward doing the same thing.I'm going to use a cutting wheel to make my cuts here and here and pretty far back on both sides, just enough to make room for our holes. This sides done, next we remove this section here. To install the rails that sit on top of the frame here, you can notch out the bed to make room for that way, or what we're going to do is loosen up the bed by taking out the bolts on the passenger side and loosen up just the driver's side, where we'll tilt it up, and then we can put our rails into place. We'll need an 18 millimeter socket. The first two are pretty easy to find. We'll point out the other two where you'll need an extension. Our next two will help to have a fairly long extension. Our last one is straight up in there. Passenger side's done. I'm going to move over to the driver's side and just loosen up the bolts.Now with an extra set of hands, you want to lift up the bed and install a piece of wood, a block or something to support it to keep it up in the air.Before we put our rails into place, we need to actually work our hitch first. Now the hitch varies from the rail and where the pins go into the rail to get underneath the truck. So we're going to have to find out what space are you between our hijacker here and these side plates. So I got one installed already, but I'm going to take it, line it up with the holes, moving back and forth and then install them, but open up the handles, make sure they go in, one on each side. Make sure they're fully locked into place, and then we can see how much gap we have. So depending on the space you have, you have two different types of plates. Of course you want to use one that fills up on both sides, and I just got these loosely in place for now. Just hold it in both sides.Okay. Once you figure out what spacers to use, then you can take your rails off when you put them inside the truck. Let's put our rails into place. I'm going to roughly line them up with the holes that we drilled out. Push them in, make sure that this part sits on top of frame on both sides.Like this. Okay. One round done. Same thing with the other one. These rails are in place. They require these shims that go between the frame and the rail, and the hole right here. It'll match it to this hole right here, so this will lift them up in this line them up position. I've got for of these, so we do it on both sides of each rail. Let's put our frame brackets into place. There is a passenger and driver's side assigned to them. To locate them, use this oval hole right here to match up to the oval hole here on the frame. When we do that, make sure that the holes in the frame line up with the bracket. These holes will line up with our cross rails here. So at this point it might be a good idea to get an extra set of hands to help hold it up while I run the bolts from here to here. So we'll use a 5/8 bolt, 1-1/2 inches long with a flat washer and then a 5/8 flange nut. Same thing on the other side.Passenger side's loosely in place. I'm going to do this one more time over on the driver's side. I got my bracket held in place by a cross rail here. I just have it finger tight, so it makes is easy to line up the holes. This 5/8 of an inch carriage bolt will go through this matching block right here. Needs to be installed from the inside out. Now the kit does give you a wire pull to do that with. To use it, we take our threaded end, we're inside the frame, there's a large round hole on the other side of the frame that you can run it through and out the other side. Take our block inside the frame. Take our bolt, thread that on to take up all the threads. Push into the frame. Wiggle it just a little bit, so it goes to that block, and then it comes out through the other side of the frame.Carefully unthread it. Okay, hold it in place. And then thread on the flange nut. We'll repeat that same process with this hole here. And also same thing over on our driver's side.We went ahead and took her hitch and put it into place and put it in the rail, so we make sure it stays nice and square. And make sure for clearance everything works all right. At this point we'll go back underneath the truck now and tighten down all our hardware as specified in the instructions.One thing before we tighten down all our bolts, I like having all my hardware in place to make sure everything lines up correctly, but when you tighten down these two bolts here, they're going to interfere with each other. So what I'm going to do is take this nut back off, take my bolt leader, put it back on there, push it out of the way, and tighten this hardware up and also the rest of them. And then come back to this one and tighten it up. Kind of be careful with it so you don't push the bolt inside.We're finished for our passenger side. One more time over on the driver's side. With all our hardware tightened down, we can go back and reinstall our exhaust. That seems to work easiest by starting the one at the rearmost of the vehicle and working your way up. Now finished for the Underbed Rail Installation Kit for a Demco Hijacker UMS fifth wheel and gooseneck trailer hitches, part number DM8551010 on this 2015 Chevrolet Silverado 2500.


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