TowWorks Trailer Hitch Lock Pins 5/8" Keyed-Alike 3-Pack, Extra-Long 3-1/4" Span with Rubber O-Rings

TowWorks 79633 is a three-pack of keyed-alike 5/8" extra-long hitch locking pins designed to secure Class III and IV 2" and 2.5" trailer receivers.

This 3-piece set combines heavy-duty steel construction with a push-and-quarter-turn tubular lock, rubber components to reduce rattle, and a removable spring clip for quick coupling changes. Each kit includes six identical keys so all three locks open with the same key, rubber caps to protect the cylinder from grit and moisture, and multiple O-rings for tailoring fitment inside various receiver tubes.

Will this fit my trailer hitch and ball mount?

The TowWorks 79633 locks use a 5/8" diameter pin with a maximum active span of 3-1/4", made for Class III and IV hitches with 2" or 2.5" receiver tubes. They are not universal—some adjustable channel-style mounts and specific brands are incompatible.

• Fits: 2" x 2" and 2.5" x 2.5" receiver tubes with 5/8" pin hole.
• Does NOT fit: CURT channel-style adjustable ball mounts (45900, 45901, 45902) and CURT adjustable pintle hooks (45907, 45908).
• Also incompatible with Andersen Rapid Hitch kits and FASTWAY adjustable ball mounts.
• Not for use with threaded bike rack connections or 1/2" pin hole hitches.

How does the locking system work and what security features are included?

The lock uses a tubular key mechanism that locks with a simple push and 1/4-turn action, while a rubber cap shields the cylinder from moisture and dirt. For redundancy, each pin comes with a separate spring (cotter) clip so you can secure the hitch quickly without the keyed lock if needed.

• Tubular keyed-alike cylinders: 6 identical keys included for all three locks.
• Push-to-lock and 1/4-turn release for easy operation under load.
• Rubber dust cap protects the lock from corrosion and grime.
• Spring clip offers an alternate, mechanical retention method—must be inserted when using lock.

How do I keep the hitch pin from rattling and adjust fit?

To minimize noise and create a snug fit inside different receiver tolerances, the set includes multiple rubber O-rings you can stack or remove as needed. Those O-rings cushion the pin, reducing vibration and wear between pin and receiver tube.

• Includes 18 rubber O-rings so you can customize spacing and snugness.
• Add or remove O-rings to accommodate slight differences in tube inner width.
• Rubber cap and O-rings together help prevent metal-on-metal rattle and moisture intrusion.

What comes in the package and how should I prepare before buying?

Each package contains three 5/8" locking pins keyed alike, six tubular keys, three spring clips, three rubber caps, 18 O-rings, and an instruction manual. Before purchasing, measure your hitch receiver inner dimensions and confirm the pin hole diameter to ensure compatibility.

• Package: 3 locking pins, 6 identical keys, 3 spring clips, 3 rubber caps, 18 O-rings, manual.
• Measure receiver tube and pin hole to confirm 5/8" diameter and up to 3-1/4" active span fit.
• If you need more keyed-alike locks, consult related TowWorks SKUs for larger sets.

Who is this for: The TowWorks 79633 set is suited for owners of Class III or IV trailers, trucks, or tow vehicles who need a compact, keyed-alike locking solution for 2" and 2.5" receivers. It's a practical choice for fleets, families with multiple trailers, or anyone wanting a coordinated set of durable locking pins with options to reduce rattle and protect the locking cylinder from the elements. Verify fitment against the incompatible models listed before purchase to avoid mismatches.