Motor1 Reviews Team Take:

Best Trailer Hitch Lock
MasterLock Universal 389-DAT

A top Amazon pick with unbeatable value.

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Runner-Up
Reese Towpower Coupler Lock

An adjustable lock with bright warning colors.

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Best
Lock Design
MasterLock 377-DAT

A trailer tongue lock with adjustable options.

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Best
Locking Hitch Pin
Curt 5/8-Inch Pin Trailer Hitch Lock

A high-quality hitch pin lock for any 2.0-inch receiver.

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Best
Heavy-Duty
Reese Towpower Heavy-Duty Lock

A very sturdy upgrade to ward off tough opponents.

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Imagine you’re on a camping trip and you’ve come back from a hike only to discover your mobile trailer is gone. Unfortunately, trailers are still susceptible to theft like any other item, but this is where the best trailer hitch locks can come to the rescue. Trailer hitch locks prevent your trailer from being coupled to another vehicle. There are many good reasons to use such a lock, with peace of mind being the first and foremost. And at a fraction of the cost of replacing a trailer, investing in a great trailer hitch lock has long-term benefits.

Our product review team has tested and reviewed the top five best trailer hitch locks on the market. We break down everything from fit to durability to give you the most comprehensive review possible. Although many locks act as a preventative measure, no lock is absolutely theft-proof and each has its pros and cons.

Best-Rated Trailer Hitch Locks

The trailer hitch locks in this article went through two rounds of reviews. We started by searching Amazon for top products, looking at factors like Prime shipping eligibility, customer ratings, Amazon superlatives, and prices.

The locks that best met these standards were ordered by our team for testing. A team member tested each product on a car, taking note of how well the lock fit our trailer, its accessibility, and its value. Each trailer hitch lock was given a rating out of five stars based on these criteria.

What Are The Best Trailer Hitch Locks?

Based on ease of use, accessibility, and value, we think the best trailer hitch locks are:

Overall (Out of 5.0 Stars)AccessibilityFitValue
Masterlock Universal 389-DAT5.05.05.05.0
Reese Towpower Coupler Lock4.75.04.54.5
Masterlock 377-DAT4.75.05.04.0
Curt 5/8-Inch Pin Trailer Hitch Lock4.54.04.55.0
Reese Towpower Heavy-Duty Lock4.54.05.04.5

Trailer Hitch Lock Ratings: Our Testing Process

The following characteristics were used to rate each lock during our testing process:

  • Accessibility: This measured how easily the trailer hitch lock opened or closed using its given set of keys. We also determined how difficult it was to try and take each lock from our trailer.
  • Fit: Based on how snugly each lock fit to our trailer hitch, it earned more points. Locks that were loose, jangly, or could be maneuvered on the hitch while attached lost points.
  • Value: Each lock’s materials, price, and warranty were researched to determine if they held their value over time. Locks made of more durable materials and were offered at a lower price than others gained points.

Why Trust Us

Each year, we review over 350 auto products. Our team of product experts thoroughly researches top products and tests items on real vehicles when possible before making our recommendations.

We publish hundreds of product and service reviews to give car enthusiasts detailed guides on automotive tools, detailing kits, car seats, pet products, and more. For more information on our testing methodology and how we evaluate every product, check out our methodology page here.

Trailer Hitch Lock Reviews

Five of the best trailer hitch locks that were tested and reviewed by our auto product team.

Trailer hitch locks come in several styles and sizes. When comparing trailer hitch locks, in addition to cost you should compare fit (available sizes), and warranty.

CostFitWarranty
Masterlock Universal 389-DAT$26.99 1 7/8"; 2.0"; 2 5/16"Lifetime
Reese Towpower Coupler Lock$17.99 1 7/8"; 2.0"; 2 5/16"One-year
Masterlock 377-DAT$36.70 1 7/8"; 2.0"; 2 5/16"Lifetime
Curt 5/8-Inch Pin Trailer Hitch Lock$20.39 5/8" diameter pinLifetime
Reese Towpower Heavy-Duty Lock$36.05 1 7/8"; 2.0"; 2 5/16"One-year

1. MasterLock Universal 389-DAT: Best Trailer Hitch Lock

  • Fit: Most 1 7/8-, 2.0-, and 2 5/16-inch couplers
  • Rust and corrosion-resistant
  • Bright red deterrent color
  • Limited lifetime warranty
  • Can be purchased in one-, three-, or four-pack
MasterLock Universal 389-DAT
MasterLock Universal 389-DAT
$28.46 Amazon

The MasterLock Universal 389-DAT offers a universal fit, so this lock pairs with various 1 7/8-, 2.0-, and 2 5/16-inch coupler sizes. The exterior of the lock is chrome to prevent rust and corrosion while a forged steel body improves both security and longevity.

Although the 389-DAT’s advanced locking system prevents picking and prying, users can easily secure and remove the lock with the included keys. MasterLock even provides a limited lifetime warranty on their locks, guaranteeing a full refund in the event that a lock may not have been a strong enough deterrent.

MasterLock Universal 389-DAT Review

The MasterLock Universal 389-DAT is the ideal choice for anyone who needs to securely park their trailer and wants peace of mind when doing so. And with its steel construction at a reasonable price, the 389-DAT provides unmatched security.

The MasterLock Universal 389-DAT attached and installed to a trailer hitch.

Review CategoryScore (Out of 5.0 Stars)
Value5.0
Fit5.0
Accessibility5.0
Overall Rating5.0

MasterLock Universal 389-DAT: Our Experience

Based on our experience, we rated the MasterLock Universal 389-DAT lock at 5 out of 5 stars. It is strongly built but also accessible in a pinch, plus we admire its ease of use and security at a competitive price.

  • Accessibility: Using the provided keys, the 389-DAT opened and closed with little hassle. We had no problems attaching and removing the lock from our trailer coupler. A drawback, however, is the keys to the 389-DAT are not unique, so there is a possibility that a key from another 389-DAT could open your lock.
  • Fit: The 389-DAT fit snugly to our coupler and required little adjustment to create a sealed lock.
  • Value: Made with forged steel and chrome, the 389-DAT is made of sturdy materials yet didn’t break the bank.

What Customers Are Saying

Amazon review score: 4.7 out of 5.0 based on over 15,000 ratings

Most of the positive reviews focus on the 389-DAT’s easy installation. There are also a high number of customers who claimed thieves attempted to steal their trailers but couldn’t due to the 389-DAT’s superior durability. Despite the high number of positive ratings, negative reviews highlighted the 389-DAT’s poor performance in harsh wintry environments.

2. Reese Towpower Coupler Lock: Runner Up

  • Fit: Most 1 7/8-, 2.0-, and 2 5/16-inch couplers
  • Aluminum body and heavy-duty steel lock bar
  • Adjustable ratchet design
  • Bright yellow theft-deterrent color
  • One-year limited warranty
Reese Towpower Coupler Lock
Reese Towpower Coupler Lock
$16.99 Amazon

Even at its incredibly low price, the Reese Towpower Coupler Lock outperforms most other hitch locks on the market. The steel lock bar is nearly impenetrable while the bright yellow color warns would-be thieves to stay away. Its U-shaped design is very simple to install, plus offers various fits thanks to its 11 adjustable positions.

The Towpower Coupler fits most 1 7/8-, 2.0-, and 2 5/16-inch couplers, making it universally versatile. While it may stand strong against a lockpicker’s arsenal, the keys are unfortunately not unique to each lock and can open other ones of the same model.

Reese Towpower Coupler Lock Review

Reese is a dependable name in the lock industry, so it stands to reason that the Towpower Coupler Lock is a worthwhile investment. This lock should help prevent anyone from tampering with your trailer.

The Reese Towpower Coupler Lock attached and installed to a trailer hitch.

Review CategoryScore (Out of 5.0 Stars)
Accessibility5.0
Fit4.5
Value4.5
Overall Rating4.7

Reese Towpower Coupler Lock: Our Experience

We had a positive experience with the Towpower Coupler, which led us to rate it at 4.7 stars. It has many similarities with our top overall pick for best trailer hitch locks but loses some points for its materials and fit.

  • Accessibility: The Towpower Coupler’s adjustable arm made fastening the lock to our trailer quick and painless. Both keys worked well, too.
  • Fit: Despite the Towpower Coupler’s ratchet arm, it did not fit as snugly to our hitch as we had hoped. It rattled slightly since the trailer ball was a bit small for the receiver, yet was nowhere close to being removable.
  • Value: While its price is extremely competitive with other locks, the body of the Towpower Coupler is aluminum. This metal is more prone to weather damage and scratching than others, so its long-term value may not be as high as locks made with stainless steel.

What Customers Are Saying

Amazon review score: 4.6 out of 5.0 based on over 16,000 ratings

Positive reviews acknowledge the Towpower Coupler as a great theft deterrent. Users are pleased that this lock is easy to use and offers effective security.

One of the most common complaints that customers have about the Towpower Coupler lock is about sizing. Reese insists the distance between the ball mount and lock shackle holes is 4.5 inches, yet some Amazon customers say their locks don’t fit due to shorter-than-advertised width.

3. MasterLock 377-DAT: Best Lock Design

  • Fit: Most 1 7/8-, 2.0-, and 2 5/16-inch couplers
  • Zinc nickel-plated body for reduced rust and corrosion
  • Front access keyway
  • Advanced locking mechanism
  • Limited lifetime warranty
MasterLock 377-DAT
MasterLock 377-DAT
$36.70 Amazon

The MasterLock 377-DAT may look like something from the distant future, but its present-day security is real and very strong. Its gray zinc nickel-plated body reduces rust and corrosion even in the toughest elements.

The 377-DAT has a front access keyway with three adjustable positions that make installation a breeze. This doesn’t compromise its advanced locking system, either.

MasterLock 377-DAT Review

The MasterLock 377-DAT is perfectly designed for easy access and a very tight fit with little adjustments. Our product review team recommends this lock to anyone who’s willing to spend a few extra bucks for increased durability and a stable fit.

The MasterLock 377-DAT attached and installed to a trailer hitch.

Review CategoryScore (Out of 5.0 Stars)
Accessibility5.0
Fit5.0
Value4.0
Overall Rating4.7

MasterLock 377-DAT: Our Experience

The 377-DAT earned a rating of 4.6 stars for its accessibility and comfortable fit. It is relatively expensive compared to other locks.

  • Accessibility: The front access keyway and adjustable locking positions made attaching the device to our trailer no problem. Unfortunately, like the other locks we tested, the 377-DAT can be accessed by anyone who bought the same lock and has keys.
  • Fit: The adjustable setting on the 377-DAT made securing a tight fit incredibly easy. Once attached properly, we weren’t able to slide the lock around or move it in any way.
  • Value: The 377-DAT is a bit more expensive than other locks of similar value. Its zinc body may be strong but is more susceptible to wear and tear over time.

What Customers Are Saying

Amazon review score: 4.6 out of 5.0 based on over 1,600 ratings

There are countless positive reviews that praise the 377-DAT’s strength. Some customers even claim to have caught potential thieves unsuccessfully attempting to steal their trailers because the 377-DAT wouldn’t budge against hammer blows. A few of the negative reviews wished the 377-DAT had chrome plating instead of zinc for extra protection against the weather.

4. Curt 5/8-Inch Pin Trailer Hitch Lock: Best Locking Hitch Pin

  • Fit: 5/8-inch diameter pin with nearly 3.0-inch usable pin length
  • Barbell-style body
  • Fits 2.0-inch receivers
  • Watertight keyhole dust cap
  • Black powder coat finish
  • Limited lifetime warranty
Curt 5 8-Inch Pin Trailer Hitch Lock
Curt 5/8-Inch Pin Trailer Hitch Lock
$22.16 Amazon

When you’re on the go with your trailer and don’t want to detach it from your vehicle, a locking hitch pin fastens the two together so thieves can’t separate them. The Curt 5/8-Inch Pin Trailer Hitch Lock has a reinforced carbon steel body that makes it an ideal theft deterrent. Its black powder coat and watertight keyhole dust cap are weather-resistant for almost any condition.

The Curt Pin Hitch’s locking head can be unlocked with a quarter-turn of the key for easy access, making it one of the best trailer hitch lock options. And because it installs into a vehicle’s receiver, there’s minimal risk of this lock being thwarted by bolt cutters.

Curt 5/8-Inch Pin Trailer Hitch Lock Review

The Curt 5/8-Inch Pin Trailer Hitch Lock can keep your camper or travel trailer safely secured for parking overnight. The unlocking mechanism can be sticky, though, so be careful when detaching it.

A close-up image of the Curt 5/8-Inch Pin Trailer Hitch Lock.

Review CategoryScore (Out of 5.0 Stars)
Accessibility4.0
Fit4.5
Value5.0
Overall Rating4.5

Curt 5/8-Inch Pin Trailer Hitch Lock: Our Experience

While the Curt Hitch Pin installs with no fuss and has an incredibly simple yet sturdy design, it is difficult to remove and scratches easily. We give it a 4.5-star rating overall.

  • Accessibility: Linking the Curt Hitch Pin Lock through our trailer mount wasn’t very difficult, and the pin locked easily. When trying to remove it, though, the lock wouldn’t come unfastened and required a few tries before we were able to get it off. Like the other locks in this review, it can be accessed with keys purchased from the same model.
  • Fit: This lock was not adjustable, so it’s one-size-fits-all or bust. It fit effortlessly into our trailer receiver but did have some wiggle room that caused rattling.
  • Value: In terms of price, the Curt Hitch Pin is reasonable. Its carbon steel body is incredibly strong as well as rust and corrosion-resistant, so it should have a long life.

What Customers Are Saying

Amazon review score: 4.5 out of 5.0 based on over 16,000 ratings

A common subject among the reviews is not the quality of the lock, but the keys that come with it. There are multiple complaints that the keys are made of plastic and break off too easily inside the Curt Hitch Pin when trying to lock it. Other reviewers are not happy with the dust cover, which they also say fell off of their locks quickly after buying. Some reviews claim that adding O-washers to each side of the lock improves its fit significantly.

5. Reese Towpower Heavy Duty: Best Heavy Duty Lock

  • Fit: 5/8-inch diameter pin with nearly 3.0-inch usable pin length
  • Barbell-style body
  • Fits 2.0-inch receivers
  • Watertight keyhole dust cap
  • Black powder coat finish
  • Limited lifetime warranty
Reese Towpower Heavy-Duty Lock
Reese Towpower Heavy-Duty Lock
$36.05 Amazon

A popular upgrade to the Reese Towpower Coupler Lock, the Reese Towpower Heavy-Duty Lock adds a few extra features to improve security. Its sturdy aluminum body, for example, is a heavier weight than its hollow counterpart. The Heavy-Duty Lock also has a much thicker steel arm for increased durability.

All things considered, the Heavy-Duty Lock does share many likable features with the Reese. For example, it also has universal compatibility, 11 adjustable locking positions, and a 1-year limited warranty. Both are theft-deterrent colors, but the Coupler’s yellow burns a bit brighter than the Heavy-Duty’s silver coat.

Reese Towpower Heavy Duty Review

For an upgrade to the Coupler, the Reese Towpower Heavy-Duty Lock is our top pick. It’s designed to withstand nearly any attempt to break it and is backed by the Reese name for quality assurance.

The Reese Towpower Heavy Duty attached and installed to a trailer hitch.

Review CategoryScore (Out of 5.0 Stars)
Accessibility4.0
Fit5.0
Value4.5
Overall Rating4.5

Reese Towpower Heavy Duty: Our Experience

Our review team gives the Heavy-Duty Lock a 4.5-star rating for its hefty design. It was very difficult to take off of our testing trailer due to its sticky keyhole, but its superior strength is worth noting.

  • Accessibility: Bolting the Heavy-Duty Lock to our trailer was easy, but removing it proved to be a challenge. The keys got easily jammed and took careful finagling before we could safely remove them without damaging the lock. This lock can also be accessed by anyone who has a key from the same model.
  • Fit: This lock fit snugly over the receiver and was able to secure a tight fit thanks to its thick steel arm. The hitch ball was still slightly too small.
  • Value: Its price competes with those of similar locks, but it has an aluminum body that may not hold as well over time. This means the Heavy-Duty lock is also prone to weather damage if not treated properly.

What Customers Are Saying

Amazon review score: 4.3 out of 5.0 based on over 4,000 ratings

Top reviews for the Heavy-Duty Lock are mixed. Some customers believe it to be a very well-designed lock that offers improved protection against thieves, while others claim their locks broke on first use. The most common complaint is about the quality of the keys and locking mechanism. However, the vast majority of reviews are positive and praise the Heavy Duty Lock’s construction.

Best Trailer Hitch Locks Buyers Guide

Before you start shopping for trailer hitch locks, it can be helpful to know about the different types of locks, materials, and more.

What Is A Trailer Hitch Lock?

Trailer hitch locks are designed to prevent thieves from stealing your trailer by attaching the hitch to their own vehicle. There are three types of trailer hitch locks: coupler, pin, and wheel.

  • Coupler hitch locks lock into the receiver on a trailer so a trailer cannot be attached.
  • A pin or receiver hitch lock, secures the receiver to the trailer hitch so the two can’t be separated.
  • Wheel locks act as a boot that prevents a trailer from rolling.

Lock Material

Many trailer hitch locks are made of heavy-duty steel or other corrosion-resistant metals to improve security and durability. Locks made with materials such as aluminum should be considered carefully because of their potential to rust when exposed to grime and other contaminants, which decreases their strength.

Size

Unlike combination padlocks, trailer hitch locks are secured with a unique key. The most common hitch locks are designed to fit 1 7/8-, 2.0-, and 2 5/16-inch trailer hitch mounts. These are generally Class I or II trailers, but most of these are designed to fit Class III and above, as well.

Best Trailer Hitch Lock: FAQ

*Data accurate at time of publication. Products subject to availability.