A rear locker transforms the Tacoma's on-trail capability on loose terrain, rocks, and mud — the ARB Air Locker is the highest-performing option, but the Auburn ECTED or Eaton ELocker deliver most of that capability at significantly lower cost.
The Toyota Tacoma uses an 8.4" ring gear rear differential (sometimes noted as the Toyota 8" or R180 in other Toyota documentation). The 2005–2013 2nd gen Tacoma and 2016–2023 3rd gen share the same basic rear axle housing, but the 3rd gen (specifically the 2014+ carrier — which actually carries through to the 3rd gen) uses a slightly revised carrier design. Confirm your model year and axle code (on the axle tag at the differential cover) against the locker manufacturer's fitment chart before ordering.
The ARB Air Locker is the gold standard for air-actuated lockers. When the locker is disengaged, the rear diff behaves like a standard open differential — no on-road handling compromise. When you flip the switch and air pressure engages the locker, both rear wheels are locked together regardless of traction differential. The engagement is reliable, immediate, and there's no ratcheting or clicking behavior on-road when disengaged. The tradeoff is the air system: you need a compressor, air lines routed to the diff, and a solenoid. Most ARB locker installs add a dedicated on-board air compressor (ARB twin or single compressor, $400–$700).
The Auburn ECTED and Eaton ELocker are electrically actuated — the engagement mechanism is electromagnetic rather than pneumatic, so no air system is required. The ECTED engages fully when activated and behaves identically to an open diff when off. For most trail use the behavior is indistinguishable from the ARB in practice. The Spartan Locker is a budget automatic locker (always locked) — it works but creates understeer on paved corners and clicking noise on tight turns on pavement. Reserve the Spartan for a dedicated trail rig or a vehicle rarely driven on pavement.
| Part | Vendor | Est. price |
|---|---|---|
| ARB Air Locker for Toyota 8.4" Rear Differential (Tacoma) | ARB 4x4 Accessories | ~$799 |
| Auburn Gear ECTED Electric Locker for Tacoma | Auburn Gear | ~$599 |
| Eaton ELocker for Toyota 8.4" (Tacoma) | Eaton | ~$699 |
| Spartan Locker for Toyota 8.4" | Spartan Locker | ~$229 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.