LockNLube GC81042 Locking Grease Coupler XL Lock & Lube

The LockNLube GC81042 Grease Coupler XL is a high-pressure, locking grease coupler that fits all standard grease guns and Zerk fittings (SAE and Metric). With nearly 4 inches of reach, this XL version is built for tough-to-access fittings on U-joints, PTO shafts, axles, and harvester heads. The coupler locks on with a simple thumb lever, forming a leak-proof seal that stays secure even under extreme pressure—up to 10,000 PSI. Once locked on, you don’t need to hold it in place, giving you both hands free to operate your grease gun safely and effectively.

Compatible with pneumatic, manual, and electric grease guns, the GC81042 is engineered for reliable, no-mess greasing in the shop or field. The four hardened steel jaws snap firmly onto the Zerk fitting, and the patented sliding sleeve ensures you can release the coupler cleanly—even if the fitting becomes pressurized. Designed with maintenance professionals, farmers, fleet operators, and equipment owners in mind, this coupler eliminates frustration and wasted grease while protecting your machinery.

LockNLube Locking Grease Coupler XL At a Glance

• Locks on and stays on under pressure: Creates a secure, leak-proof seal even at 10,000 PSI
• Hands-free operation: No need to hold the coupler during greasing, making the job safer and faster
• Extra reach – 3.6” effective length: Access hard-to-reach or recessed fittings with ease
• Quick-release thumb lever: Disconnect easily, even from pressurized fittings
• Fully rebuildable: Replace the internal seal and jaws without purchasing a new unit
• Fits all standard grease guns: Connects to 1/8” NPT outlets, including manual, air, and battery-powered guns
• Durable construction: Hardened steel jaws and nitrile rubber seal stand up to heavy use

Markets

• Agriculture & Farming Farmers use this tool to grease recessed fittings on balers, harvesters, and PTO shafts without disassembly or struggle.
• Heavy Equipment & Construction Essential for greasing joints and pivot points on excavators, loaders, and dozers where fittings are often shielded or dirty.
• Fleet Maintenance & Trucking Keeps axles, suspension systems, and driveshaft U-joints serviced efficiently with minimal downtime.
• Forestry Equipment Access hard-to-reach fittings on harvesters and forwarders with the extended reach and locking mechanism.
• Industrial & Manufacturing Used in preventative maintenance programs to improve consistency and reduce greasing time in busy operations.
• DIY & Home Mechanics Ideal for home garages with ATV, trailer, or small engine maintenance needs—especially for those tired of messy grease jobs.
• Municipal & Utility Crews Supports maintenance of public equipment, from garbage trucks to utility trailers, where efficiency and cleanliness matter.

This tool is especially valuable for heavy equipment maintenance, where time is tight and access to grease points can be difficult. Whether servicing a shielded fitting deep inside a machine or a weathered joint on the job site, users can rely on the LockNLube XL to get grease exactly where it’s needed—without mess or hassle. The rebuildable design means you can replace the seal and jaws instead of buying a new coupler, keeping costs down over time.

LockNLube GC81042 Locking Grease Coupler XL Lock & Lube Features

• Rated to 10,000 PSI! Locks on, stays on. Does not leak once locked on.
• Hands-free – does not pop off under pressure.
• Easily release from fittings with the thumb lever, even at extreme pressure.
• No more broken Zerks
• Over 3.5″” of reach. Great for shielded PTO shafts, axles, harvester heads, U Joints and other recessed grease fittings.
• Fits all standard Grease Guns – 1/8 NPT fitting. Fits all SAE and Metric Zerk fittings. Simply replace your existing coupler.
• Includes rebuild . Easily replace seal and jaws without replacing the coupler.
• Old/retired SKUs for this product include: GCXL, GC81032.

LockNLube GC81042 Locking Grease Coupler XL Lock & Lube Specifications

• Maximum Pressure: 10,000 PSI (690 bar)
• Grease Gun Compatibility: Fits all pneumatic, manual, and battery-powered grease guns
• Thread Type: 1/8” NPT female
• Zerk Compatibility: Fits all DIN and SAE standard grease fittings
• Length: 5 in (127 mm)
• Effective Reach (Nose to trigger): 3.6 in (91 mm)
• Diameter (Front of Coupler): 5/8 in (16 mm)
• Weight: 5.8 oz (164 grams)
• Seal Type: Nitrile rubber
• Construction: Four hardened steel jaws
• Rebuildable: Yes (seal and jaws are replaceable)
• Patented: US Patent #8,955,544

Why Professionals Choose the LockNLube Locking Grease Coupler XL Lock & Lube

The LockNLube XL grease coupler is known by techs, farmers, and mechanics as the go-to fix for leaky couplers, hard-to-reach Zerks, and busted knuckles. Whether you call it a grease tip, locking fitting, or grease gun upgrade, this is the tool that finally stops the mess. It keeps your work clean, your hands free, and your equipment in top shape. If you’re tired of grease going everywhere but the fitting—this is the upgrade that gets the job done right.