Locker Upgrade Path for Power Wagon (Factory + Tru-Lok or ARB Bulletproofing)

Difficulty 4/56–12 hrs$0–18002014-2018, 2019-2024, 2025+

The Power Wagon comes from the factory with electronic locking front AND rear differentials — the only production truck in North America that does (no Raptor, no TRX, no Tacoma TRD Pro). For 95% of owners, the factory lockers are bulletproof and never need upgrading. This entry covers the 5% case: aftermarket replacement when a factory locker fails, or when you want a more rebuilable unit for serious rock-crawling.

The Power Wagon's factory Tru-Lok system is genuinely unique:

The factory units are NOT "limited slip" — they're real selectable lockers. When engaged, 100% of axle torque is split 50/50 between the wheels. Performance is on par with aftermarket ARB or Eaton units.

For 95% of Power Wagon owners: the factory lockers never need upgrading. Common issues are wiring (solenoid faults from corrosion at the connector) or actuator failures — these are repairs, not upgrades. See front-locker-elocker-troubleshooting.

The 5% case where an aftermarket locker swap makes sense:

  1. Factory locker has physically failed (cracked case, broken splines) — out of warranty, a new factory unit is $800-1,400 from Mopar. ARB or Eaton replacement is comparable cost, often with longer-term parts availability.
  1. You want a rebuildable unit for hard rock-crawling. Factory Tru-Loks are sealed; ARB Air Lockers and Eaton ELockers can be field-rebuilt with replaceable internals. Worth it if you wheel 50+ days/year in rocks.
  1. You've re-geared and don't trust the factory carrier shim stack. When the diff is open for a re-gear, swapping to ARB or Eaton at the same time saves labor. About $300 extra labor + the locker cost. See pw-regear-456.

For ARB Air Lockers ($1,200 + compressor ~$400) — proven rock-crawl reference, needs an air compressor (Power Wagon owners often install one for tire airing-up anyway, so this is a small marginal cost).

For Eaton ELockers ($1,100, no compressor needed) — electronic activation like the factory unit, more straightforward wiring. The pick if you don't want to plumb air lines.

For aftermarket front: don't bother. The factory front locker is excellent and rarely fails. If it does fail, replace with factory Mopar.

For aftermarket rear: ARB or Eaton are both excellent. Choose based on whether you're running an air compressor anyway.

Honest framing: this is a $1,200 swap that 95% of Power Wagon owners will never need. The factory lockers really are that good. Read this entry as "what to do IF a factory unit fails" — not "what to install on a stock truck."

A "failed" locker is far more often a wiring or actuator fault than a broken carrier. Before you condemn a sealed Tru-Lok and order a $1,200 ARB, work the cheap causes:

  1. Pull codes. The Tru-Lok system reports through the BCM; a C-code pointing at the front or rear locker circuit usually means a solenoid or connector fault, not mechanical failure.
  2. Inspect the axle-mounted connector. The rear locker connector sits low and forward of the AAM 11.5" pumpkin and collects mud and salt. Corrosion here mimics a dead locker exactly — clean it, dielectric-grease it, retest.
  3. Confirm engagement conditions. The rear auto-engages in 4-Low and can be switched manually; the front only engages in 4-Low with the rear already locked. Owners regularly report a "broken" front locker that is simply being asked to lock in a mode the truck won't allow.

The full electrical walk-through lives in front-locker-elocker-troubleshooting. Only after the wiring and actuator check out clean does an aftermarket carrier enter the conversation.

Replacing the rear Tru-Lok with an ARB or Eaton is a full third-member rebuild — pull the axle shafts, drop the carrier, and re-set up the ring and pinion. This is the job where most owners pay a shop, and rightly so:

  1. The AAM 11.5" carrier comes out as an assembly; mark and save the bearing caps and shims in order.
  2. The new carrier needs backlash and pinion-bearing preload set to spec with a dial indicator and inch-pound torque wrench. Get this wrong and the gearset howls or fails.
  3. ARB requires an air line plumbed from a compressor to the diff with a bulkhead fitting; Eaton needs a switched 12V feed and ground. Route either away from the exhaust and rotating parts.
  4. Because the diff is already apart, this is the moment to re-gear if you're planning it anyway — combine the labor. See pw-regear-456 for ratio choices on 37s.

Realistic cost: $1,100-1,200 for the locker, plus $400 for an ARB compressor if you don't have one, plus $400-700 shop labor for the setup. Combining with a re-gear adds the gearset but only marginal extra labor.

Don't replace the front with aftermarket. The factory AAM 9.25" front Tru-Lok is excellent and parts-supported through Mopar; an aftermarket front locker buys you nothing but wiring headaches. If the front truly fails out of warranty, a factory replacement is the right call.

Match the locker to how you actually wheel. ARB's air system is the rock-crawl reference and is field-rebuildable, but it adds a compressor and air lines that need maintenance. Eaton's ELocker engages electrically like the factory unit with far simpler plumbing — the better pick if you don't already run air for tire inflation. Picking ARB purely "because it's the best" and then never maintaining the compressor leaves you worse off than the factory unit you removed.

Why it works

Trade-offs

Tools required

Parts

PartVendorEst. price
(Already factory) Tru-Lok front locker — solenoid + selector switchRam Factory~$0
(Already factory) Tru-Lok rear lockerRam Factory~$0
ARB Air Locker rear AAM 11.5" (replacement, if factory rear fails)ARB~$1200
Eaton ELocker rear AAM 11.5" (alternative replacement)Eaton~$1100

Sources

Related


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.

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