TRE 4x4 Crab Differential Locker — Deeper Locking Depth & Nickel-Plated Gears

Step up to a stronger, more secure lock with the TRE 4x4 Crab Differential Locker. This selectable locking differential (often called a diff locker/diff air locker) delivers true 100% lock on demand, then opens for normal road manners. TRE’s Crab Locker uses developed clutch gears with deeper engagement and nickel-plated wear surfaces for durability and consistent performance, making it a robust upgrade for rocks, mud, ruts and winter traction. :contentReference[oaicite:0]{index=0}

Why choose the Crab Locker?

• Deeper locking depth — upgraded clutch gear design increases engagement depth (approx. 5 mm vs 2 mm in typical units) for a more positive, secure lock under load. :contentReference[oaicite:1]{index=1}
• Nickel-plated gears — enhanced corrosion resistance and wear life for long-term reliability. :contentReference[oaicite:2]{index=2}
• Pneumatic locker — switchable in the cab (requires onboard air) for precise, repeatable control. :contentReference[oaicite:3]{index=3}
• Wave-spring actuation — compact, resilient springing that supports smooth lock/unlock and gear strength. :contentReference[oaicite:4]{index=4}
• Oil return & leak-resistant architecture noted in third-party listings — helps prevent oil migration into air lines and reduces common leak risks. :contentReference[oaicite:5]{index=5}
• 5-year warranty and UK advice from OFM4x4.

What’s included

• TRE 4x4 Crab Differential Locker assembly
• Bulkhead fitting & nylon air line
• 12V solenoid valve
• Dash-mounted switch with wiring pigtail
• Fittings & install hardware (application-dependent)

Not included: carrier bearings/shims, gear oil, or the on-board air compressor. Add a compressor and, for dual lockers, an air manifold.

How it helps

• Off-road control: locks both wheels on an axle together for maximum traction.
• On-road manners: switches back to open diff for tight turns, parking and daily driving.
• Confidence in bad weather: assists on slippery surfaces where open diffs struggle.

Installation & setup

• Professional install recommended: set carrier bearing preload and backlash to factory spec.
• Route airlines away from heat/moving parts; pressure-test before final assembly.
• Pair with on-board air (single or twin) and an air manifold if running front + rear lockers.

You might also need

• Air Compressors — for diff locker actuation & tyre inflation.
• Air Accessories — manifolds, pump-up kits, fittings.
• Other Differential Lockers — browse more options.

FAQs

1) What is a diff locker?
A differential locker (or diff air locker) locks both wheels on an axle together for maximum traction off-road.

2) How does the Crab Locker differ?
It features deeper gear engagement (approx. 5 mm) and nickel-plated gears for improved durability and a more positive lock. :contentReference[oaicite:6]{index=6}

3) Do I need a compressor?
Yes. It’s a pneumatic locker. Use an onboard air compressor; add a manifold for multiple lockers. :contentReference[oaicite:7]{index=7}

4) Is it road-legal?
A selectable locker behaving like an open differential when disengaged does not by itself establish road approval. Compatibility and lawful use depend on the exact vehicle, installation and destination. Follow the manufacturer's engagement instructions; do not engage on high-grip road surfaces or where doing so could impair safe steering or handling.

5) What’s included?
Locker assembly, solenoid, airline, dash switch and fittings. Bearings/shims and the compressor are sold separately.

6) Will it handle larger tyres?
Yes — within the limits of your axle, gearing and driving style. The engagement depth and plating are designed for hard use. :contentReference[oaicite:8]{index=8}

7) Is it leak-prone?
Designs referenced in retailer specs highlight leak-resistant actuation and an oil return system to help protect air lines. :contentReference[oaicite:9]{index=9}

8) What’s the warranty?
TRE provides a 5-year warranty on the locker unit (see terms with your order).

Explore related categories: Differential Lockers • Air Compressors • Air Accessories