Trailer Jack Hack




About: I am a hard working individual. I am into electronics and mechanics mainly but can get into anything if it has to do with making our lives easier or more enjoyable.

Awhile ago, I decided to change the outriggers/loading stabilizers on the rear of a 20' flatbed tandem trailer from the original design to a standard trailer jack.

I regret that I don't have any pictures of the original outrigger design. It wasn't very complicated. It featured a piece of pipe that slides in another larger pipe welded to the trailer frame with three positions for a stop pin. One position was transport, and the other two positions were for loading.

While this setup worked, there were a lot of problems with it.

1. If you didn't load the trailer on perfect level pavement or driveways, the outriggers didn't support the trailer properly because side to side they didn't hit the ground evenly. This usually ended up in blocking which also wasn't a very precise process and required carrying blocks.

2. When in loading position, they still stuck up above the deck of the trailer. That was fine until you tried to load something that is slightly wider than the deck of the trailer. Like a vehicle with large tires, or equipment. They tended to be rough on tires, or more blocking was required.

3. When in transport position, they stuck up about two feet above the deck of the trailer. That was fine until you attempt to haul something wide or long.

4. Most times, when you finally did get something loaded, the weight of the load prevented you from easily lifting the outriggers back into transport position.

I could probably go on but I won't. They were clunky at best. So they got replaced with something that worked better. This new setup has worked great for a couple of years, but still had room for improvement.

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Step 1: The Main Problem

The trailer jack works great as an outrigger.

1. Its adjustable for uneven ground or desired load support.

2. It mounts underneath the level of the trailer deck.

3. When the trailer is loaded it can easily be released.

4. It rotates into transport and tucks out of the way, or can be completely removed without ever breaking a sweat.

The main problem with this setup is that the when loading something that is wider than the trailer deck and also ends up right over the jack area, the load prevents you from turning the handle around to release the support tension. I set out to find a solution for this problem and maybe speed things up in the process.

Step 2: Remove Cover Bolts and Cover

This step is pretty easy. This style of jack has a cover that features two bolts that attach it to the main jack body. Once those are out simply remove the cover to reveal the simple 90 degree gear setup.

Step 3: Find the Pin and Drive It Out

In my jack, there was two pin slots in the back side of the gear. This pin serves two purposes. It holds the handle in the jack head, but it also keys the handle to the gear. Drive this pin out, and the handle slides right out.

Step 4: Measure the Size of the Handle

Originally, I had planned on cutting the handle off straight and welding something to it (like a nut) or something like that which would allow you to turn the jack in increments on the lower 180 degrees of operation if the handle was blocked on the upper 180 degrees of operation.

After measuring the handle that came out of the jack it immediately became apparent that it would be so much easier to use an off the shelf standard 1/2" grade 5 bolt. There would be no fabrication of great magnitude from this point on to accomplish what I was after. The bolt I chose was 5.5" long.

By the way, the calipers don't really read the same as they do in the pictures but between the handle and the bolt its only a few thousands off. The bushings the manufacturer chose to use in the jack as well as the gear are, well, not exact either.

Step 5: Cut the Bolt and Mark/drill Pin Hole

I used an angle grinder fitted with a cut-off wheel to cut the threaded section off of my bolts(I made two because I have two jacks). I then used a bench grinder to smooth the cut up and slightly bevel the cut edge. Its probably not entirely necessary but I don't like sharp edges and it looks nice.

To mark the hole, I measured from the end of the handle that sticks out of the back of the jack body to the hole. I then transferred the measurement to the cut off bolts. Once marked, I center punched and drilled the pin hole in the drill press. After drilling, I made a slight edge bevel with a larger drill bit. This helps greatly in pin installation.

To determine the right size of drill bit to use, I measured the pin and found the closest size drill bit undersize, meaning it will fit tight and stay put. It was only a few thousandths smaller if I remember right. I would specify but odds are, if you're interested in doing this you may have a different jack, or pin size, etc. It is best to make your own measurements and double check.

Step 6: Fit the New Handle

Slide the bolt into place, lining up the hole with one of the slots in the backside of the gear. Drive the pin back in with appropriate punch. Take this opportunity to redistribute the grease within the jack into the bushings and high wear areas.

Step 7: Test It Out

Reinstall the cover and you're back in business. At this point, you have many options for operation of the jack. You can use a wrench, ratchet with a socket, or as pictured, a cordless drill. (I wouldn't recommend using a battery cordless/air impact gun because it seems like the impact action would damage the gears with the impact action). The cordless drill on low however, is awesome. It has plenty of power to operate the jack normally enough to lift the trailer. Beyond that, who doesn't love adding motors to something? At the very least, it takes the slack out in a hurry, and when it comes time to operate the jack under load, one could just switch to a ratchet to go slower and more carefully.

Step 8: Results

The results out of this project are as follows:

1. I ended up with two perfectly good handles that could be used in another project.

2. The jack as an outrigger is low profile and operates exactly how I want it to.

3. The cost for this modification is negligible weighing in at two 1/2" X 5.5" grade 5 bolts.

4. They even store easier as there is no big floppy handle catching on everything they possible can.

I'm pretty happy with the way everything turned out. Let me know what you think!

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    14 Discussions


    2 years ago

    Great hack. I am going to do this to the tongue jack using the same size bolt head as the stabilizers already on the trailer, then I can use the same speed wrench/socket size for all!

    1 reply

    Reply 2 years ago

    Sorry for the late reply, I've been busy for quite sometime. If you end up doing it, you should take a picture and post an 'I made it' comment back on here. If not, no worries, I just like to see when things work out:)

    Thanks for commenting and checking it out!


    4 years ago

    Take one of the crank handles, grind the end square to fit your socket.
    Now you have a manual backup for the day when your cordless drill battery is dead. It'll be faster than using a ratchet.

    2 replies

    Reply 4 years ago on Introduction

    That. Is. A. Great. Idea! Believe it or not, that's what the original design mimicked in my head. Only in my mind, I was going to just weld a socket to the handle. Not wanting to dedicate a socket to the job at the time, and figuring out I didn't need to cut the handle at all, I kind of abandoned the idea. But grinding it down...grinding it down...that could work nicely. It's already 1/2" so you'd kind of be stuck using 3/8" drive unless you used some square keystock and welded it to the handle...Anyway just thinking out loud haha. Thank you for the comment. I may or may not edit that part in to the end of this instructable. If I did, would you mind if I used it? I'd totally give you credit for the idea.


    Reply 4 years ago on Introduction

    Feel free to use the idea as you like.

    I was thinking you could weld a socket to the end, too. I figured a single socket wouldn't cost too much.

    Or you could just buy a speed wrench.


    4 years ago on Introduction

    "Awesome" seems to be the best word here. Not only is this a well executed solution, the thinking can be used in other similar situations. The tongue jack on my cheapy H/F 4x8 trailer is getting this fix. Thank you. Great 'ible.

    1 reply

    Reply 4 years ago on Introduction

    It's awesome to hear there are other ideas coming out of this project. That's why I don't really like to get super specific with any of these because sometimes I feel like it could restrict an adaptation of the idea, which could be way better in the first place. Far too often, I find myself working on fabrication projects and getting stuck in the mindset of the original design. Later on, if I rethink it, or step back while building I'll get another idea that would work better, faster, cheaper, easier, etc.


    I hate to pull a "search engine" here, but did you mean linear actuator? Haha only kidding. Yeah, I mean honestly it wouldn't be that hard to just attach a motor drive shaft directly to the jack itself instead of using this method and there you go. A worm gear motor (I think that's what they are called) comes to mind so that it would mount parallel to the body would work awesome. I'm pretty sure most linear actuators use the same principle action of a screw jack.


    4 years ago

    Awesome idea - thanks for the nudge to do something similar.

    1 reply

    Hey, thanks! And thank you for checking it out and commenting. It'd be cool to see your similar project.


    4 years ago

    That is great! I totally understand all the problems that you were having and this is an awesome solution.

    1 reply

    Thank you! Yeah, its pretty frustrating when you know loading something on a trailer safely and efficiently shouldn't be that hard. These help out quite a bit. Sometimes its the little things.