The best cargo trailer door lock depends on the door: a replacement latch suits a compatible entry-door cutout, while a puck or disc padlock is intended for a door with a hasp or compatible locking point. The Siasky is best for specified trailer entry-door openings, the Proven Industries set for enclosed-trailer rear and side doors, and the Master Lock set for general trailer and storage use. CAMJOKE and ONNAIS offer alternatives for buyers who need a replacement latch or keyless entry.
| Product | Best suited for | Lock type |
|---|---|---|
| Siasky Black RV Door Lock | Specified entry-door cutout | Replacement latch |
| Proven Industries Puck Lock Set | Enclosed trailer rear and side doors | Puck padlock |
| Master Lock 40TRI | Trailer, garage, shed, and storage use | Disc padlock |
| CAMJOKE RV Door Lock | Compatible hinged entry doors | Replacement latch |
| ONNAIS Keyless RV Door Lock | Keypad or remote entry | Keyless replacement lock |
Siasky Black RV Door Lock
This replacement latch is best for owners whose trailer entry door has a 3.63-by-2.71-inch lock opening. The manufacturer lists horse trailers, cargo haulers, travel trailers, and campers as intended uses. Its zinc alloy construction is described as corrosion-resistant, scratch-resistant, and oxidation-resistant.
The package includes one lock and four alike keys, and the lock supports key removal in both positions. It was selected because its listed use explicitly includes cargo haulers and its cutout dimensions are provided for fit checks. Limitation: it is a replacement latch, not a puck lock for securing a rear barn door or hasp. Measure the existing opening before ordering.
Proven Industries Puck Lock Set
This three-lock set is best for enclosed-trailer owners who need padlocks for rear or side doors with compatible lock points. Its hidden, shielded shackle is designed to reduce access for bolt cutters and resist prying, while the listed pick-resistant cylinders add another layer of resistance to tampering.
The bodies are made from 6061 aluminum, and all three locks are keyed alike. Each lock includes two keys. It was selected for its stated trailer-door purpose and the convenience of using one key across the set. Limitation: check the lock point against the listed shackle opening and depth before purchase; the product does not replace an existing built-in entry-door latch.
Master Lock 40TRI Disc Padlocks
This three-pack of keyed-alike disc padlocks is best for buyers securing a trailer, garage, shed, or storage area with a compatible hasp. The product lists stainless steel construction, a hardened steel shackle, a four-pin cylinder, and a dual locking lever mechanism. Its shrouded design limits exposed shackle area.
Choose this set if you want multiple locks operated with the same key and the trailer has a suitable locking point. It was selected as a general-purpose trailer padlock option rather than a built-in latch replacement. Limitation: fit depends on the door and hasp dimensions; the listing advises checking backset, cross bore, and door thickness.
CAMJOKE RV Door Lock
This replacement lock is best for a compatible hinged trailer or camper entry door measuring 3.75 inches tall by 2.75 inches wide at the cutout, with a door thickness of 1.25 to 1.5 inches. The listing specifies right-side hinges and includes four keys, instructions, and screws in various lengths.
The lock uses a zinc alloy and plastic construction and is described as IP66 waterproof, UV-resistant, and corrosion-resistant. It was selected for its stated use in travel trailers, camper vans, trucks, and cargo carriers. Limitation: it is not listed for Class A or Class C RVs or glass doors, and hinge direction and dimensions must match.
ONNAIS Keyless RV Door Lock
The ONNAIS lock is best for trailer owners who want keypad or remote access instead of relying only on a conventional key. Its listed features include a keypad, a remote FOB with a stated range of up to 100 feet, and a hidden mechanical key for backup. The manufacturer describes the body as all-metal and weatherproof.
It was selected for buyers who value multiple entry methods or need to share temporary access without handing out a key. The listing says one battery replacement can power up to two years of use. Limitation: the product page describes it as fitting most trailers and fifth wheels but provides no cutout measurements here, so verify fit before purchase.
Buying Guide: How To Choose A Cargo Trailer Door Lock
Do you need a replacement latch or a padlock?
A replacement latch fits into a door’s existing cutout and operates as the entry-door lock. A puck or disc padlock attaches to a compatible hasp or locking point, making it a more relevant type for many enclosed trailer rear and side doors. Confirm the door hardware can accept a padlock before choosing one.
Which measurements should you check?
For a replacement latch, compare the cutout height and width, door thickness, and hinge orientation with the product specifications. For a padlock, check the hasp opening and the padlock’s shackle dimensions. Measurements help prevent ordering a lock that cannot be installed or closed correctly.
Do you want keyed or keyless access?
Keyed-alike sets can simplify managing several padlocks with one key. A keypad-and-FOB lock offers alternative ways to enter, but still check the fit requirements and plan for battery replacement. A mechanical backup key can be useful when electronic access is unavailable.
What construction details matter?
For outdoor use, compare the listed materials and weather-related features. The products here describe materials such as zinc alloy, aluminum, and stainless steel, as well as corrosion or weather resistance. These descriptions do not replace checking that the lock suits the trailer’s exposure and hardware.
Frequently Asked Questions
Can an RV entry-door lock secure a cargo trailer rear door?
Not necessarily. An entry-door replacement latch requires a matching cutout, while rear doors often use hasps or other external locking points. Match the lock type to the door hardware.
What is a puck lock used for on a cargo trailer?
A puck lock is a padlock intended to secure a compatible hasp or locking point. The Proven Industries set is specifically described for enclosed-trailer rear and side doors.
How do I know if a replacement trailer latch will fit?
Measure the existing cutout and door thickness, then compare them with the product specifications. Also verify hinge direction when the listing requires it.
Are keyed-alike locks useful for trailers?
Keyed-alike locks let one key operate multiple locks in the same set, which can reduce the number of keys needed. Confirm that the set’s locks suit each intended locking point.
Is a keyless trailer lock completely key-free?
Not always. The ONNAIS model includes a hidden mechanical key as backup, alongside its keypad and remote FOB.