TowWorks Trailer Hitch Lock 5/8" Hardened Pin Extra-Long 3-1/4" Span for 2" & 2.5" Receivers, Keyed Unique

TowWorks 79631 is an extra-long, keyed-unique 5/8" trailer hitch locking pin designed to secure 2" and 2.5" Class III and IV receivers with a 3-1/4" active span.

This sturdy hitch lock combines a hardened steel 5/8" pin, a push-to-lock tubular mechanism, and rubber O-rings to reduce rattle, offering a reliable way to keep trailers, cargo carriers, and accessories secured. It arrives keyed unique (two tubular keys included) and includes a separate cotter-style spring clip for redundant security. The black e-coated over zinc-plated finish improves corrosion resistance while a watertight dust cap helps protect the lock core.

How does the TowWorks 79631 fit different hitch receivers?

The 79631 features an extra-long active length of up to 3-1/4" so it spans deeper or offset hitch tubes found on many Class III and IV setups. It is sized to work with both 2" and 2.5" (2-1/2") receiver openings when measured against your hitch dimensions. Always confirm your receiver and accessory tube thicknesses before buying to ensure the correct fit.

• 5/8" hardened steel locking pin for heavy-duty applications
• Maximum active span: 3-1/4" to clear thicker tubes or adapters
• Compatible with 2" and 2.5" (2-1/2") receivers when dimensions match
• Check receiver wall thickness and accessory shank length before purchase

What security features stop theft and reduce noise?

TowWorks combines mechanical and practical features: a tubular push-lock core keyed unique, a separate spring (cotter) clip for redundant retention, and rubber O-rings to eliminate play that causes rattles. The lock core is protected by a rubber dust cap to limit corrosion, and the zinc-plated plus black e-coat finish increases durability in outdoor conditions.

• Two tubular keys provided, each lock keyed unique
• Separate spring clip can be used as backup retention
• Rubber O-rings reduce rattling and hold the pin steady
• Watertight rubber dust cap shields the locking mechanism

How easy is the TowWorks 79631 to use and maintain?

The push-to-lock design requires only a quarter-turn with the tubular key to secure the pin, making installation quick. The included spring clip allows use without engaging the keyed lock if you prefer a simpler backup fastener, though the cotter pin must be installed for safe use. Occasional lubrication of the tubular core and rinsing of salt and dirt will prolong lifespan.

• Push lock with 1/4-turn tubular key operation for fast locking/unlocking
• Can be used with or without the lock mechanism when spring clip is in place
• Maintenance: rinse off road salt and apply light lock lubricant as needed
• Do not omit cotter pin when using without locking core for safety

Why choose a keyed-unique option versus keyed-alike?

This 79631 model is each keyed unique — useful when you need separate keys for different trailers or to prevent one key opening multiple locks. TowWorks offers keyed-alike alternatives (79632, 79633, 79630) if you prefer a single key for several locks; choose the SKU that matches your keying preference and quantity requirements.

• 79631: each lock keyed unique (two keys included)
• 79632/79633/79630: available for keyed-alike quantities, choose accordingly
• Unique keying increases compartmentalized security across multiple users
• Keyed-alike simplifies access when managing several locks with one key

Who is this for: The TowWorks 79631 suits vehicle owners, contractors, and recreational users who need a longer locking pin for thicker or deeper receiver setups on Class III and IV hitches. It’s ideal if you want a corrosion-resistant, anti-rattle hitch pin with a keyed-unique tubular lock and the option to use a cotter-style spring clip for extra safety. Confirm your receiver and accessory measurements before ordering to ensure a proper fit.