Zerk Fittings

The Zerk Fittings category gathers replacement grease-fitting components designed to make lubricating moving RockJock joints, suspension links, steering components and shackles simple and efficient. These fittings support easy maintenance, extended joint life, and smoother performance under off-road or heavy-use conditions. Whether you’re building a custom suspension, maintaining a trail rig, or refurbishing rod ends or joints, zerk fittings allow clean greasing without disassembly. To ensure you are following the correct lubrication procedures for your specific components, please refer to our Instruction Manuals.

What Are Zerk Fittings & Why They Matter

• Definition & function – A Zerk fitting (also known as a grease fitting or grease nipple) is a small metal valve installed into joint housings, chassis components, or link ends that allows grease to be injected under pressure, then seals to keep contaminants out.

• Lubrication access point – Using a grease gun, fresh lubricant can be pushed into bearings, pivots, rod ends, or bushings to ensure smooth operation and reduce friction and wear, especially in high-articulation suspension systems.

• Contaminant protection – A spring-loaded internal ball valve closes when not in use, blocking dirt, dust, and water from entering the joint and helping preserve internal components over time.

• Maintenance-friendly design – Greasable joints with Zerk fittings allow periodic servicing instead of full replacement when grease breaks down, making them ideal for long-term builds and heavy-use rigs.

Common Zerk Fitting Types & Typical Uses

• Straight-thread grease fittings – Standard fittings (commonly 1/4"-28 UNF or metric equivalents) that thread directly into joints, rod ends, control arms, or pivot housings for general suspension and steering lubrication.

• Angled grease fittings (45° / 90°) – Designed for tight or hard-to-reach areas where straight fittings would be difficult to access with a grease gun.

• Replaceable and serviceable fittings – Used in rebuildable rod ends and suspension joints, allowing repeated greasing and long-term service instead of discarding worn components.You can find these essential maintenance parts through authorized service centers via our Dealer Locator.

Fitment & Typical Applications

• Used in suspension joints, control arms, steering links, rod ends, shackles, and other pivot points exposed to motion, load, dirt, and moisture.

• Common on off-road, rock-crawling, and lifted-suspension systems where frequent articulation and environmental exposure demand regular lubrication.

• Ideal for custom builds and fabrications where serviceable, long-life joints are preferred over sealed or disposable components.

• Suitable for a wide range of mechanical systems—including automotive, agricultural, and industrial—where bearings, bushings, or pivots require periodic lubrication under load.

If you have questions about fitting sizes or compatibility with your custom build, please Contact Us for expert technical support.