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Best Trailer Hitch Lock Options of 2020: Tow Safe!

As compared to other vehicles, trailers are relatively easy to steal and sell off. It is, therefore, essential to install an effective locking mechanism that will secure them against theft.

Ordinary chain and padlock combinations, like those used to protect bikes, are not practical for trailers. They are too easy to cut with bolt cutters, and it's also possible to break them open with a heavy object.

You need a lock that can support your trailer’s weight. You need to consider the strength of the lock material, the locking mechanism, and the lock keys.

The Best Trailer Hitch Locks

Master Lock Trailer Coupler
Tow Ready Coupler Lock
CURT Coupler Lock

1. Master Lock Trailer Hitch Lock

The coupler lock from Master Lock is compatible with different trailer coupler sizes — 1-7/8 inch, 2 inches, and 2-5/16 inches. Therefore, when you buy a new trailer, there is no need to get a new lock with it. You can always reuse an existing coupler lock.

Since the lock is constructed from galvanized steel — that is, steel coated with a protective layer of zinc — it can withstand dust, dirt, and various weather conditions without rusting or corroding.

The chrome-colored lock’s advanced locking mechanism is difficult to pick and pry open. Given this combination, it is likely that this tough and rugged lock will be a very effective deterrent for most would-be thieves.

Even those wielding hammers won’t find it easy to break this lock, so you can be reasonably sure that it will be able to keep your trailer safe.

Also, apart from trailers, you can use the coupler lock to secure many other towing vehicles and RVs.

2. Tow Ready 'Gorilla Guard' Coupler Lock

You can use this strong stainless-steel lock only for 2-inch trailer couplers. Moreover, the lock’s specifications state that the coupler’s width, including its lip, can’t exceed 3-13/16 inches.

Also, as per these specifications, the coupler lip's height can’t be more than 5/16 inch. For the lock mechanism to work, the lock must fit into the trailer’s ball socket, and its solid steel bar must wrap around the coupler. This design shields the lock from tampering devices and provides excellent protection for unattended trailers.

The lock works on a push-and-lock system. Once you unlock it, you can remove the key, as you won’t need it again for re-locking. The key, incidentally, goes in from the lock’s bottom, thus making it hard for anyone to drill through the lock. At the same time, this feature demands some flexibility on your part since locking and unlocking with the key will require bending over.

The lock can survive heavy hammer blows, sustaining very little damage to its super-heavy-duty structure. Even if a would-be thief tried using a grinder on this lock, it would take such a long time that it wouldn’t be worth their time.

3. CURT Trailer Hitch Lock

The CURT coupler lock is supposed to protect your trailer from thieves when you decide not to hitch it to your vehicle. When you fix the lock to the trailer hitch, it ensures that the trailer ball cannot go into the coupler.

The lock is compatible with flat couplers as well as rolled lip couplers, and it’s available in two sizes: 1-7/8 inches and 2 inches. Furthermore, while the lock's industrial grade aluminum body is lightweight, it is also extremely tough and difficult to break. It will prevent anyone from easily stealing the trailer, camper, or boat that you use it on.

Additionally, the lock’s grey powder coating will protect it from water and heat. This is a lock that you can safely use in all weather conditions.

4. AMPLOCK Coupler Lock

This heavy-duty cylinder lock weighs a whopping 12 pounds. It is made of stainless steel and heat-treated steel as well as ducted cast iron. While these high-quality materials make the lock rust-resistant, they also impart it with enough strength to withstand sledgehammer blows. In the worst-case scenario, the material will absorb the shock and cause the lock to fold. However, it still won’t break.

Essentially, it is also a difficult-to-pick lock since its rotating face prevents drilling. This disk-based lock comes with a control and identification key system that scans and identifies the lock’s user before unlocking.

The lock’s molded and swivel design perfectly fits the unhitched 2-5/16-inch coupler of a trailer or an RV. Given this perfect fit, it is impossible for thieves to insert any device to break the lock.

5. Trimax Stainless Steel Receiver Lock

The receiver lock is made of 100 percent stainless steel and has one of the strongest currently available locking pins. You can fit the 5/8-inch pin to all class III, IV, and V receiver hitches. Additionally, thanks to this pin, the lock has a head pull strength of 5,800 pounds.

The lock’s extended 3-1/2-inch span can fit the wide receivers on Ford, Toyota, and other trucks. It has an O-ring seal that keeps water, dirt, and grime out of the locking mechanism. Also, there is a protective watertight rubber cap to shield the keyhole.

To lock and unlock the pin, it will be enough if you turn the rugged tube key only a quarter of the way. The type A key has seven pins and is spring-loaded, making it highly secure. In addition to this, the lock itself is difficult to drill.

What to Look for in a Trailer Hitch Lock

trailer hitch

While a trailer without a lock is an easy target, installing a lock will not necessarily guarantee complete security. If the thieves are determined enough and have the time to break the lock, they may get away with stealing the trailer.

However, locks do work as a preventive measure to a certain extent. Hard-to-break locks, for instance, may force would-be thieves to give up and leave before they attract public attention. Installing a trailer hitch lock is, therefore, a must for all trailer owners.

Let’s look at the three types of hitch locks that you can use to safeguard our trailer:

Types of Trailer Hitch Locks

Receiver Hitch Lock

After you have hitched the trailer to your vehicle, you can install this lock in the fastener hole in the towing vehicle's receiver. With the receiver hitch lock in place, it will be difficult for anyone to unhitch the trailer.

Coupler Lock

You want your trailer to remain safe even when you don’t hitch it to the vehicle. This is where a coupler lock can help. These locks are U-shaped, and you can install them over the coupler on the trailer’s tongue. They deter thieves from hooking their vehicle to your trailer and driving away.

Chock Lock

Chock locks are similar to the tire locks that prevent vehicle tires from moving, and they function in the exact same way. They fit over the wheels of your trailer or RV and curb wheel movement. Thus, they can protect our trailer from would-be thieves.

Lock Factors to Consider

Lock Build Quality

The most common way to break a lock is to smash it hard with a hammer or a heavy object. Locks of lightweight metals like aluminum or zinc can fall apart when hit with force. However, since you want your lock to be more durable than that, you should look for ones made of materials that don’t fracture easily.

High-quality stainless-steel locks or those of hardened steel are much stronger. Still, apart from the lock’s build quality, it is also essential that we check the build quality of the key. Ideally, it should also be tough and not bend, crack, or break.

How Much Does the Trailer Weigh?

Trailer hitches come in assorted sizes for securely towing trailers of different weights. The hitch classes range from Class I to Class V and determine the trailer weight that a towing vehicle can pull.

The Class I hitch, for instance, can support 2000 pounds while the Class II hitch and the Class III hitch can support 3500 pounds and 6000 pounds, respectively. Furthermore, the Class IV hitch supports 10000 pounds, and the Class V hitch supports 12000 pounds.

Also, the hitch class specifies the hole size for inserting the receiver pin or tube. Since the Class I and II hitches have 1-1/4-inch holes, we will need a 1/2- inch diameter pin for them. On the other hand, the Class III and IV hitches have 2-inch holes, and the Class V hitch has a 2-1/2 -inch hole. For these three hitches, we will need to use 5/8-inch diameter pins.

The hitch lock has a pin that locks the receiver and the hitch together. To determine the hitch class we ought to use and to know the pin size for that class, we must consider the trailer weight that we will be towing. The lock must support the trailer weight, and its pin must secure the hitch and receiver. Otherwise, it can break and cause an accident.

Is the key unique?

Some brands use the same key design for all the locks of a particular model, and some may even use the same key for a variety of different locks.

In such a scenario, it is easy for experienced thieves to steal a trailer. They generally have extensive selections of keys, and they can use these to attempt unlocking the lock by trial and error.

Naturally, we want to avoid putting our property at such a risk. For that reason, it is essential to check whether the lock we are buying has a unique key.

It is a good idea to seek out brands with at least a million lock and key combinations. After making our purchase, we should keep the packaging or note down the unique code of our key to avoid any trouble if we ever lose or break it.

Can You Get a Duplicate Key?

Even if you do everything in your power to safeguard your lock keys, you may misplace or lose them at some point.

When that happens, what are your options? Will the manufacturer provide another key? If the key is unique, how will they confirm that it isn’t a thief that is making the request? Is it possible to get the neighborhood locksmith to create a duplicate key for your lock? These are all the things we must consider when buying a trailer hitch lock.

Is the Lock Weatherproof?

An essential factor to consider is if the lock is a good choice in regard to the local weather conditions. Exposure to sunlight, rain, or snowfall shouldn’t destabilize the lock and hamper its performance. Also, you need to make sure that the lock and the key are made of materials that won’t rust and corrode. More importantly, you must check that the lock’s keyhole has a weatherproof cap.

For Which Types of Hitches Can You Use the Lock?

Some locks are universal, and you can use them to secure a variety of hitches. In addition to towing, you can use trailer hitches for managing cargo and bike racks.

When buying a trailer hitch lock, it’s essential to check if the lock is compatible with the types of hitches you need. Since the manufacturer’s specifications include this information, it will help to read through them before making a purchase.


There are various preventive measures that you can take to secure your trailer, like clamping the wheels, installing a car alarm system, and installing a GPS tracking device. Moreover, you can mark it with a distinctive sign and always park it in open public areas.

However investing in a lock like the ones we recommended above is a wise decision. By making it difficult for anyone to steal the trailer, they can secure your property and grant some peace of mind.


Richard Reed
I've been a General Manager of a moving company and I've also been a Professional Mover for over 30 years. I've driven flat beds, reefers, dropdecks, moving vans, heavy machinery, etc. In my time as a Mover I've driven over 1,000,000 safe miles. My days of moving and driving truck are past me but The Vehicle Lab allows me to share the knowledge I've gained over the past 40 years.

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