Troubleshooting Demco Hijacker Jarring and Chucking at Start and Stop

Question

Question:

apparently have one of the earlier versions of the 18K demco hijacker, no matter how many times I adjust it, when I have come to a stop and then take off it feels like there is slack in something and it jerks and pops , it operates fine except that, is it the design with just the locking bar or something else ? I see the new head has a traditional locking device, and looks more secure, was wondering if this is a fix for the clunking ?

asked by: Gary G

0

Expert Reply:

I reached out to my contact at Demco and he said that depending on the year, there was a gear adjustment bolt on the cab side of the base of the older Hijacker models. He also said some of the slide bar heads had an adjustment bolt there as well for a better king pin/pin box connection. These adjustments should clean up the slop that you are experiencing. If you have your owners manual it will walk you through those adjustments. If you don't have the manual, let me know your model number and send a photo and I'll see what further troubleshooting we can do.

expert reply by: Jason S

0

To M.

6/9/2025

What way do you do? Adjust the bolt to stop the jerking

Kate F.

6/10/2025

@ToM Since you have the older version with the locking bar design, there is going to be some slop in the jaws. The thing is, that locking bar can sometimes leave a little slack or play between itself and the king pin. It’s not dangerous, but it can create that annoying feeling like something’s shifting around when you stop and start. It’s especially noticeable in heavier trailers or under load. There are a couple of things you can try to reduce the jerking. On many of those bar-style hitches, there’s a small adjustment bolt that controls how snugly the bar fits around the king pin. You can tighten that just a little bit, like 1/8 of a turn at a time, until it holds things more securely. Just be careful not to overdo it, since overtightening can affect how the latch operates or even wear on the pin. Also, it helps to inspect the bar and channel for any visible wear and give everything a good cleaning and lubrication with fifth-wheel grease. Dry metal surfaces can exaggerate movement, and a bit of lube goes a long way in smoothing things out. If things are still clunking after that and you want to look into getting a new hitch, let me know your year, make, model, bed size, and if you have the OEM Prep Package or not so I can find a better hitch for you.

Answer 1

Yes, fortunately, you do have a couple of options that will allow you to use your Demco Hijacker 18K Fifth Wheel #DM8550034 on your 2020 Ford F-250 with the OEM Prep Package. Your first option is to use the Demco 5th Wheel Rail Adapter #DM6175, which…

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Answer 2

Hi Jeff; it does sound like you need to adjust the gear adjustment bolt as seen in the picture below. Try this first to see if it solves the problem. If not, feel free to reach back out in the comments below and I will help you troubleshoot further.…

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Answer 3

Hey Michael, thanks for reaching out. So, this is actually normal for the Demco autoslide, and to be honest, it is one of the only downfalls of their hitch design. It takes a tremendous amount of force to rotate the head, so if you disconnect at an…

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Answer 4

In regards to a Demco Autoslide 5th Wheel Trailer Hitch like part #DM8550034, there are not adjustments for the locking jaw mechanism. If there is too much slop inside the jaws with the kingpin they are either too far worn or damaged and need…

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Answer 5

To me that looks like one of the urethane bumpers #DM15469, so you'll want to replace that first. This was most likely caused by wear and tear as the clunking I believe to be related to your capture plate needing to be adjusted. What you're…

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Answer 6

Hey Scott, I just got the Demco wear plate 14711 added to our selection under part #DM48KV.

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Answer 7

You ordered the correct urethane dampener for your Demco Hijacker AutoSlide part #DM8550024. The 15769 and the 15469 basically represent the same part number now so the #DM15469 that you ordered will fit and work well!

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Answer 8

It sounds to me like the gears of the slider inside of your Replacement Head and Base Assembly for Demco Hijacker Autoslide 5th Wheel Trailer Hitches #DM6077 may either have debris blocking them, the teeth may be chewed up and need to be replaced, or…

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Answer 9

Hey George, thanks for reaching out! The Demco Autosliding Hijacker is one of my favorites when it comes to 5th wheel hitches. When did you pick it up? Have you inspected the gear system yet? There is a snippet from the instructions (see attached…

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Answer 10

If you're having issues coupling to your Demco Hijacker Autoslide 5th Wheel Trailer Hitch w/ Slider - Single Jaw - Above Bed - 18,000lbs the jaws could need to be greased but it could also be the handle or the internal springs. When pulling the…

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Answer 11

Thank you for your purchase from etrailer of the Demco Hijacker Autoslide 5th Wheel Trailer Hitch #DM8550034. When it comes to the clunking you are hearing, the most likely issue is the capture plates needing to be adjusted, as these do need to be…

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Answer 12

We don't offer a video, but that's a great idea that I'll suggest to our shop manager. The maintenance procedures for the Demco #DM8550040 Hijacker Autoslide 5th wheel hitch are outlined in the linked owner's manual, but the keeping…

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Troubleshooting Demco Hijacker Jarring and Chucking at Start and Stop

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