Hit The Road, Jack

While the jack that came with your boat trailer works OK, here's why you might want to consider swapping it for something better.

When you bought your trailer boat, there was almost certainly a jack already on the trailer. And chances are good that it’s the same jack attached to it today. In some cases, that’s just fine, but in others, you might be making your trailering life tougher by sticking with that old jack. Truth be told, few boaters ever replace them unless necessary. But here’s why you might want to reconsider.

Why Swap Out That Old Jack?

The first reason is if it’s failing or has failed. You don’t want to miss out on a voyage because your old jack made a crunching noise when you were getting ready to hitch up and go. Another reason is because a better jack can make hitching, moving, or storing your boat a little easier.

You have three basic options: swing jacks, fixed jacks, and power jacks. Swing jacks pivot on their mount to sit in a horizontal position while trailering. This minimizes the chances of the jack hitting something while you’re on the road and reduces the amount of cranking you need do every time you hitch up the boat. As soon as that wheel is off the ground you can swing it up and out of the way. With a fixed jack, you’d need to keep cranking (and cranking, and cranking) to get as much clearance between it and the road as possible.

Fixed jacks may take a ton of cranking, but they can also take a ton of weight. No matter how big your boat is, if it can be trailered there’s a fixed jack that can handle the job. Swing jacks, on the other hand, generally top out at 1,000 to 2,000 pounds of tongue weight capacity. On the flip side of the coin, fixed jacks usually aren’t wheeled (and those that are, tend to have relatively low weight capacities). That means that moving the trailer without it being hitched up is impossible.

Power jacks are fixed jacks with an electrical advantage: Simply hit a button to raise or lower them. That sounds convenient, but it also means you may have to rig up a power source, which, in some cases, requires mounting a dedicated 12-volt battery on the trailer. And from then on, you’ll need to keep the battery charged and maintained.

In addition to these three types, there are some less common trailer jacks such as unpowered jacks with drill bit fittings that allow you to power-crank using a handheld drill (adhering to the specified limitations of both the jack and drill). There are also a few hydraulic jacks on the market.

Which One, Jack?

When it comes to replacing the jack that’s on your trailer right now, several considerations come into play. For the widest swath of boaters, a wheeled swing jack makes the most sense. It minimizes the cranking you’ll have to do, and depending on the boat’s size, in many cases you’ll be able to either move the bow around by hand or at least nudge the tongue to align it for easier hitch-ups. Note that single wheels are easier to turn on a hard surface such as concrete, but double wheels travel much better over soft surfaces such as a grassy yard.

Naturally, capacity is an overriding factor. If your rig weighs more than 20,000 pounds or so, using a swing jack probably isn’t an option. Aside from capacity, if you have a bad case of tennis elbow or just don’t like doing a whole lot of cranking, a fixed jack that’s powered (or one that accepts a drill bit) will likely prove attractive. However, some of these require more complex installation and cost significantly more than the manual variety. Jacks you crank by hand are priced anywhere from $50 to $350, and while some powered jacks fall into that range, others can cost thousands of dollars.

Another consideration is the jack’s “distance of travel,” which is how much it can raise or lower the trailer tongue. Ten to 15 inches is common, and some jacks have up to 20 inches of travel. In most cases 10 is plenty, but if your hitch is at an unusual height, you may need the extra distance. As a rule of thumb, when replacing an existing jack that worked well for your rig, matching or exceeding its travel is always a good move. Having more travel can also be helpful if you might need to hitch or unhitch on uneven terrain. Plus it allows you to crank the bow higher for better drainage of the boat during storage.

Replacement Tips

In most cases swapping out the jack is a simple DIY job. They’re generally mounted to the trailer tongue with a pair of U-bolts that go through an integrated bracket on the jack, or with a set of brackets and bolts. Replacing them means blocking the trailer tongue to remove all weight from the jack, spinning the nuts off the bolts, and sliding the old jack off. Then put the new jack into place and bolt it on.

Now, anyone who’s spent a few years launching and retrieving boats, especially in a saltwater venue, knows that trailer bolts have a nasty habit of welding themselves in place with corrosion. If the trailer is more than a few years old, there’s a good chance that removing those nuts and bolts will be a serious chore. Ease the job by giving them a thorough spritz of PB Blaster the day before you get to work, and be prepared to heat the nut with a torch and/or hit it with an impact wrench if necessary.

In some cases, a jack can be channel-mounted to the trailer frame rather than mounted on the tongue. A bracket with 90-degree angles allows for bolting directly to the upper and lower edges of a trailer frame’s I-beam. Just be sure to measure carefully, because the bracket must fit both the jack and the size of your trailer’s I-beams. There are also some A-frame mounts available that fit into the joint between the tongue and beams. (These are much more popular on utility and RV trailers and aren’t often seen in the marine world.)

In some other cases, jacks are designed to be welded on or bolted to weld-on brackets. Unless there’s a pre-existing bracket welded in place and you have a jack to match, this sort of project may be beyond the average boater’s DIY abilities. That said, when replacing a jack, there’s usually nothing problematic about using a new mounting system and leaving an old welded-on plate in place after removing the jack itself.

The bottom line? There’s a jack out there to fit every trailer, but that jack doesn’t necessarily fit every trailer boater. Fortunately, whether you need to replace a failing jack or want to make hitching up and hauling away a little easier, swapping out that jack is a straightforward job and usually one you can do right in your own driveway.