A trailer jack is a vertical device that allows you to lift or lower your trailer to ensure that it's perfectly level. The jack is positioned on the tongue of the trailer and is also used to hitch and unhitch your trailer from your truck or SUV. In short, if you have a travel trailer, you'll need a trailer jack.

However, not all trailer tongue jacks are made equal. Different jacks have different lifting capacities and not all types are the same. Let's take a closer look.

How Do Trailer Jacks Work?

A trailer jack elevates the trailer at the tongue to allow the trailer to be hooked or unhooked from a tow vehicle. Common trailer jack types include a swivel jack, an A-frame jack, and a drop-leg jack.

Trailer jacks come in many different weight and length capacities, so it's important to know the length for extended and withdrawn positions. A trailer jack's primary functions are as follows:

1. Elevate and lower the trailer for connection to the hook or disengage it from the ball.
2. Maintain the trailer in a level position if it's not hooked to a vehicle.
3. Stabilize a parked trailer for loading and unloading.

What Size Trailer Jack Do I Need?

To start, you'll need your trailer weight and trailer tongue weight, which can generally be found in your owner's manual. As a general rule, the tongue weight shouldn't exceed 15% of the overall trailer weight. However, if you have heavy items in the front of your trailer, your tongue weight might be more. The tongue weight is how much your trailer weighs when it's fully loaded.

You'll also need to know much weight is on your rear axle. Again, your owner's manual should help here. How heavy of a hitch you'll need depends on the tongue weight and a percentage of the truck's weight. It's generally preferable to have a slightly more heavy-duty trailer jack than one that is too light.

How To Install a Trailer Jack

Installing a trailer jack depends on what type you have. For example, a weld-on trailer jack is installed through a plate or ring that has to be welded to the tongue of your trailer. Bolt-on trailer jacks are installed to the tongue of your trailer with u-bolts. If you have an electric trailer jack, these must be connected to a 12-volt power source before they can be operated.

Some types of trailer jacks can be either bolted or welded onto your trailer tongue. Check for the wrench icon on any Action trailer jack page to see if professional-grade installation is offered.

How To Grease a Trailer Jack

It's a good idea to grease your trailer jack after every trip, or every month if you use your trailer regularly. If you don't grease your trailer jack often enough, it may become difficult to turn. How to grease the jack depends on the type you have.

Some models have a zerk fitting, which means you'll need to use a grease gun to apply new grease through the zerk fitting.

Otherwise, you'll usually be removing the cap and squirting in a generous amount of white lithium grease. When the trailer is attached to the tow vehicle, fold the jack up so that it isn't holding weight and squirt more grease into the moving cylinders.

After applying the grease, extend the jack until it's fully expanded and then back to fully folded. Add grease to each of these positions.

How to Use a Trailer Jack

If you have a manual trailer jack, you'll be using a hand crank to lift and lower the trailer tongue. Getting your trailer perfectly level can be quite a workout using a manual jack. If you have an electric trailer jack, the gear-driven operation will do all the work for you simply by pressing a button.

However, if you don't have access to a power outlet and your battery is dead, most electric jacks also have a manual crank that turns it into a manual jack.

Types of Trailer Jacks

There are several types of trailer jacks, but they can also be separated into categories based on whether they are electric or manual, bolt-on or weld-on. The first thing you'll want to decide is whether you want an electric or manual trailer jack.

Manual trailer jacks tend to be the cheaper option and are potentially more durable due to fewer moving parts. However, they are also potentially difficult to operate for people with physical limitations.

Electric jacks are obviously much easier to operate, but they do require a power source and are more expensive. An electric jack still has room for part failure, which could leave you with only a manual option anyway.

A-Frame Jack or Straight-Tongue

Your trailer's tongue shape will help you decide what type of jack you need. If your trailer tongue is in an a-frame shape, then you'll need an a-frame jack. To check for this, see if your coupler is mounted on the end of an a-shaped metal frame. If it's not, then it should be mounted on the end of a long steel tube, which means you'll need a straight-tongue jack.

Marine Jack

Marine jacks are basically what they sound like: jacks for boat trailers. Marine jacks are usually equipped with wheels to allow for greater mobility in coupling the trailer. These jacks also have a heavy-duty pull pin that allows them to pivot on the mounting bracket to easily get out of the way for travel. A marine jack will also generally come with a protective coating against moisture such as a zinc finish.

Swivel Jack

Swivel jacks get their name from the pull-pin swivel feature that allows the jack to swivel on its mounting bracket. This is a similar style to a marine jack. A typical pipe-mount swivel jack might feature a lift capacity of 3,000 pounds and a support capacity of 5,000 pounds with 10 inches of travel. Swivel jacks are usually for smaller trailers.

Direct-Weld Square Jack

As it sounds, this jack welds directly onto the frame of your trailer. Usually, you have two options here in a top-handle jack or a side-handle jack. A typical direct-weld square jack might be rated for 8,000 pounds support capacity and 7,000 pounds lift capacity with 15 inches of travel. These are more heavy-duty jacks versus the swivel jack.

Trailer Jack Accessories

You might also need some trailer jack accessories like a trailer jack foot, a trailer jack handle, or a jack handle knob. These accessories may or may not come with the jack you choose, but are necessary implements for using certain jacks.

Rely on Action Trucks for a nice selection of trailer jacks, including boat trailer jacks, a-frame trailer jacks, and trailer jack accessories. Look for the Wrench icon on any of our products to get professional-grade installation in any Action store.