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Good news for anyone planning a front locker upgrade on the 6th Gen 4Runner. Eaton ELocker front differential fitment is now confirmed (ON THE FRONT), and the part numbers are straightforward depending on whether you stay on factory gears or plan to regear.
Factory Gear Ratio Overview
To the best of current knowledge, all 6th Gen 4Runners run a 3.58 factory gear ratio, regardless of hybrid or non-hybrid drivetrain. That simplifies things for anyone staying stock or upgrading later.
Eaton ELocker Front Part Numbers
Regeared setups
Expected common ratios after regear will likely be 4.56, 4.88, and possibly 5.29 as the platform develops
Important Notes
If you are building a 6th Gen 4Runner for technical terrain, confirmed front Eaton ELocker fitment is a major upgrade if you actually wheel your vehicle.
In low speed technical environments such as rock crawling, steep ledges, and off camber terrain, a locked front differential provides even torque to both front wheels instead of letting one wheel spin while the other stays stuck. This reduces the need for modulating brakes for traction which prevents heat buildup in the braking system, and provides more predictable and stable behavior when climbing ledges.
Because the Eaton ELocker is electrically actuated, engagement is instant. When locked, it provides even torque between both front axles. When disengaged, the differential behaves like an open unit, preserving normal steering feel, reducing CV and axle stress during turns.
Rear ELocker fitment for the 6th Gen 4Runner has not yet been officially confirmed. There are indications that a rear solution is in development, but no part numbers or application data are available at this time. Updates will be shared once rear differential compatibility is verified.
Application guides and more on the Eaton site: https://www.eaton.com/us/en-us/catalog/differentials/eaton-elocker-differential.html
And a few shots on the Rubicon after we installed the locker. Confirmed fitment and confirmed functionality.
The Eaton front e-locker is by far one of the best mods you can do to your 6th Gen if you're looking to wheel harder.
A selectable front locker allows you to maintain open diffs during normal driving, while also being able to lock both front axle shafts together when required. This is incredibly important on IFS platforms like the 6G 4Runner, where increased traction front and rear can make the difference between making it through a steep/technical obstacle or not.
These two photos above are common scenarios on the Rubicon where a front locker can make or break a line. I've seen many vehicles struggle in sections like this throughout the con. As you approach large boulders, the front tires often have initial traction, but once the rear tires drop into a ledge or wedge against a rock, forward progress stalls. The rear axle becomes loaded and bound against the obstacle, and despite being locked, the rear tires simply spin without enough leverage to climb the ledge. At the same time, the open front differential allows torque to unload, leaving the front tires effectively doing nothing.
With a front locker engaged, torque is shared evenly across both front axle shafts, allowing the vehicle to pull itself up and over the obstacle instead of relying solely on the rear.
Obstacles like this are much easier to control when locked in the front. Sections like these still require an accurate line choice and driver skill, but a locked front diff significantly reduces wheel spin/slip, momentum-based attempts "back up and bump it", and unnecessary drivetrain stress.
Front lockers are usually one of the first mods I throw on my vehicles. They just provide a more controlled and predictable crawl through tough sections.
Factory Gear Ratio Overview
To the best of current knowledge, all 6th Gen 4Runners run a 3.58 factory gear ratio, regardless of hybrid or non-hybrid drivetrain. That simplifies things for anyone staying stock or upgrading later.
Eaton ELocker Front Part Numbers
- Factory gears (3.58) Use Eaton ELocker 3.73 ratio and down
- Part number: 14219-1
Regeared setups
Expected common ratios after regear will likely be 4.56, 4.88, and possibly 5.29 as the platform develops
- Use Eaton ELocker 3.91 and up
- Part number: 14221-1
Important Notes
- This confirmation is for the front differential only
- Rear ELocker options are not confirmed yet
If you are building a 6th Gen 4Runner for technical terrain, confirmed front Eaton ELocker fitment is a major upgrade if you actually wheel your vehicle.
In low speed technical environments such as rock crawling, steep ledges, and off camber terrain, a locked front differential provides even torque to both front wheels instead of letting one wheel spin while the other stays stuck. This reduces the need for modulating brakes for traction which prevents heat buildup in the braking system, and provides more predictable and stable behavior when climbing ledges.
Because the Eaton ELocker is electrically actuated, engagement is instant. When locked, it provides even torque between both front axles. When disengaged, the differential behaves like an open unit, preserving normal steering feel, reducing CV and axle stress during turns.
Rear ELocker fitment for the 6th Gen 4Runner has not yet been officially confirmed. There are indications that a rear solution is in development, but no part numbers or application data are available at this time. Updates will be shared once rear differential compatibility is verified.
Application guides and more on the Eaton site: https://www.eaton.com/us/en-us/catalog/differentials/eaton-elocker-differential.html
And a few shots on the Rubicon after we installed the locker. Confirmed fitment and confirmed functionality.
The Eaton front e-locker is by far one of the best mods you can do to your 6th Gen if you're looking to wheel harder.
Steep/Technical Obstacles
A selectable front locker allows you to maintain open diffs during normal driving, while also being able to lock both front axle shafts together when required. This is incredibly important on IFS platforms like the 6G 4Runner, where increased traction front and rear can make the difference between making it through a steep/technical obstacle or not.
Offset Rock Obstacles
These two photos above are common scenarios on the Rubicon where a front locker can make or break a line. I've seen many vehicles struggle in sections like this throughout the con. As you approach large boulders, the front tires often have initial traction, but once the rear tires drop into a ledge or wedge against a rock, forward progress stalls. The rear axle becomes loaded and bound against the obstacle, and despite being locked, the rear tires simply spin without enough leverage to climb the ledge. At the same time, the open front differential allows torque to unload, leaving the front tires effectively doing nothing.
With a front locker engaged, torque is shared evenly across both front axle shafts, allowing the vehicle to pull itself up and over the obstacle instead of relying solely on the rear.
Obstacles like this are much easier to control when locked in the front. Sections like these still require an accurate line choice and driver skill, but a locked front diff significantly reduces wheel spin/slip, momentum-based attempts "back up and bump it", and unnecessary drivetrain stress.
Front lockers are usually one of the first mods I throw on my vehicles. They just provide a more controlled and predictable crawl through tough sections.
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