3 Best Master Lock Trailer Locks In 2022 Reviewed

Updated Oct 12, 2021

Protecting your trailer from theft is a priority for all trailer owners. No one wants to see their investment go down the drain just because it hadn't been secured enough. After all, you've spent a lot of money on your trailer. Thus, it only makes sense to invest in reliable trailer locks and trailer hitch locks, too. With that said, if you're planning to buy a Master Lock trailer lock, we recommend that you read this review in full. We've listed and reviewed the three best trailer locks from the brand to guide you on your purchase.

Check this: Best Trailer Pin Locks

Reviews of the Top 3 Best Master Lock Trailer Locks

Master Lock Trailer Coupler Lock, Receiver Lock, and Trailer Coupler Latch Lock combo pack

Master Lock Trailer Coupler Lock, Receiver Lock and Trailer Coupler Latch Lock

Via Amazon.com

This pack contains a trailer coupler lock, a receiver lock, and a trailer coupler latch lock. Protected by a limited lifetime warranty, the Master Lock trailer lock 3794DAT also boasts a Weather Tough seal and water tight cap for additional protection from dirt and moisture.

The trailer coupler lock fits 1-7/8-inch (48mm), 2-inch (51mm), and most 2-5/16-inch (59mm) couplers. Meanwhile, the coupler latch lock adjusts from 9/16 inches (14mm) to 2-3/4 inches (70mm) in size, which makes it more flexible. 

Lastly, the receiver lock (with two L-shaped receiver hitch pins) is for both 1/2-inch (13mm) and 5/8-inch (16mm) receivers. Moreover, this receiver lock also has a Push to Lock locking mechanism, which instructs you to push the lock body firmly onto the pin to remove the key. In here you'll find a swiveling stainless steel locking head for easier use.

These are all keyed alike, and the package itself comes with two keys.

Check this: Best Gooseneck Trailer Locks - #1 Review


  • Weight: 1lb , 0.45kg
  • Product dimensions (inches): 10" (25.4cm) x 5" (12.7cm) x 4"(10.2cm)


  • Comes complete with a trailer coupler lock, a latch lock, and a receiver lock
  • Flexible application
  • Has a seal and water tight cap to ward off moisture and dirt 
  • Backed by a limited lifetime warranty


  • Relatively-pricey

What Buyers Like

Customers who've tried this Master Lock trailer lock combo pack were impressed with how easy all the components were to use. They're all applicable towards a generous range of sizes, so as long as your trailer's coupler is within the dimensions listed, you're probably not going to run into compatibility issues.

Also, the included storage pouch makes handling the locks and keys easy and fuss-free. Moreover, the fact that all the locks are keyed alike is another convenient plus. 

Next, because of reassuring features like Water Tough moisture protection, users of this Master Lock trailer lock are convinced that this product is durable and really long-lasting.

Final Verdict

It's important for the best trailer coupler locks to not only provide security, but convenience, as well. With that said, this Master Lock trailer lock is heavy and strong enough to deter thieves. Furthermore, having three separate components gives users some added peace of mind. 

This Master Lock trailer lock is then for people who don't mind paying a bit more for convenience, durability, and flexibility. Also, this is definitely the most heavy-duty lock on this list, and the fact that it comes with a bunch of extra features like Weather Tough, Push to Lock, and a lifetime warranty is just an added bonus.

Check this: Best Trailer Door Locks

Master Lock trailer coupler lock with keys and latch lock

Master Lock Heavy Duty Trailer Lock 3784DAT

Via Amazon.com

The Master Lock 3784DAT is a heavy-duty trailer lock for 2-5/16" (59mm) couplers. Furthermore, it works well with standard lip, straight lip, hammer blow, surge brake, rolled lip, and UFP coupler styles. In addition, this Master Lock trailer lock boasts a laminated steel construction and a reassuring lifetime warranty.

This lock protects your trailer from thieves using an advanced locking mechanism. This mechanism, according to Master Lock, resists prying and picking. Likewise, its key way cover protects the lock from moisture and dirt. In conclusion, these features give the impression that this trailer lock had been built to last.

The 3784DAT also includes a Keyed Alike trailer coupler latch lock, as well as two keys, in the package. Lastly, the latch lock can accommodate 9/16-inch to 2-3/4-inch adjustments, which makes it a versatile tool.

Check this: Best Reese Trailer Locks To Choose


  • Weight: 3.9lbs , 1.8kg
  • Product dimensions (inches): 9" (22.9cm) x 12" (30.5cm) x 15"(38.1cm)


  • Made with strong laminated steel
  • Fits most styles of 2-5/16-inch couplers
  • Affordable
  • Comes with a lifetime warranty


  • The lock can sometimes be challenging to unlock with the keys

What Buyers Like

This trailer lock impressed buyers because of its heavy duty look and reasonable price. Consumers also liked that both the main trailer lock and the latch lock are keyed alike, which makes the whole thing convenient to use.

Many people also reported that this lock fits very snugly into their trailers, which makes it more aggressive-looking. Lastly, the laminated steel construction has been a definite pro, as well as the fact that it fits most styles of 2-5/16-inch couplers well.

Final Verdict

As a conclusion, this affordable Master Lock trailer lock appears to have been built with long-term use and versatility in mind. If you're on the lookout for a 2-5/16-inch coupler lock and you don't want to worry about whether or not it might be a good fit for the style of couBlaylock TL-50 Gooseneck Lockpler you have, the Master Lock 3784DAT is one of the safest choices out there.

Moreover, we appreciate the fact that it comes with an additional latch lock since it is an added layer of security. The included lifetime warranty is also very reassuring. In conclusion, this lock is for shoppers who are looking for a balanced mix of affordability and security.

Check this: Best Gooseneck Hitch Reviews

Master Lock 379DAT Coupler Lock with Keys

Master Lock Trailer Coupler Lock 379DAT

Via Amazon.com

This universal trailer coupler lock from Master Lock fits 1-7/8-inch (48mm), 2-inch (51mm), and most 2-5/16-inch (59mm) couplers. Additionally, it is resistant to rust and corrosion. Also, like with all Master Lock trailer locks, it resist prying and picking through an advanced locking mechanism.

The Master Lock 379DAT is also easy to install. With the right key, it's easy to unlock and remove, as well. Moreover, it's backed up with a limited lifetime warranty, which should protect you from manufacturing defects.

If your trailer fits in the size categories listed above, this lock will then work excellently. With that said, it'll fit couplers made by Valley, Reese, Fulton, Atwood, Shelby, Hammerblow, Putnam, Dutton-Lainson, and UFP. However, note that it's a good match for standard couplers only (around or less than 8000lbs).

Finally, each package comes with a single lock and two keys.


  • Weight: 1.75lbs , 0.8kg
  • Product dimensions (inches): 2.7" (6.86cm) x 7.5" (19cm) x 6.6" (16.8cm)


  • Rust- and corrosion-resistant
  • Comes with a limited lifetime warranty
  • Reasonably-priced
  • Resists prying and picking


  • Will fit only standard couplers (around or less than 8000lbs)

What Buyers Like

Amazon reviewers have said that this Master Lock trailer lock works and looks great for the price. Furthermore, they remarked how robust and reliable the lock feels, which makes it a great deterrent against thieves. Lastly, the key hole cover is a much-appreciated feature, too.

Next, buyers have reported that this trailer lock is also easy to install and use. Because it comes with a lifetime warranty, worries about malfunctioning locks are addressed, as well. 

Final Verdict

In conclusion, if you own a standard trailer with a 1-7/8-inch (48mm), 2-inch (51mm), or 2-5/16-inch (59mm) coupler, the Master Lock Universal Trailer Coupler Lock is a reasonably-priced and adequate-secure option for you. Its heavy-duty look makes it a great deterrent against thieves. The lifetime warranty and rust- and corrosion-resistant finish also lends this Master Lock trailer lock a "made for the long term" vibe.

Check this: Best Fifth Wheel Hitch Reviews

Best Master Lock Trailer Lock For You

First, just like with gooseneck trailer locks, the best trailer locks should be strong, reliable, and easy to use. That is why through this post, we've shown the best Master Lock products that passed our standards in terms of security, value, and convenience.

Keeping in mind their individual features and specs, you're sure to find something you'll like among the models listed here. Likewise, just remember to weigh their pros and cons against your needs to know the best Master Lock trailer lock for you.

As an Amazon Influencer, we earn from qualifying purchases you might make if you click any of the links on this page.

5/5 - (2 votes)
Christelle Niña