Eaton ELocker4 Differential 36 Spline 36-Spline Toyota Tundra 10.5in

Second and third generation Toyota Tundras with the big 10.5 inch rear axle are strong trucks, but the factory carrier is still an open differential, and on a muddy two-track, a snowy boat launch or a rutted hill climb one rear tire spins while the other sits still. The Eaton ELocker4 14232-1 is the electric selectable locker for the 2007-2021 Tundra 10.5 inch rear with 36-spline axles, and it works with all gear ratios. Flip the dash switch and both rear tires turn together; switch it off and the truck drives like stock on the street.

What the ELocker4 does in a Tundra 10.5 inch rear

The ELocker replaces the factory carrier. With the switch off it acts as an open differential, letting the rear wheels turn at different speeds in corners, so handling, tire wear and daily driving stay normal. When the driver presses the switch, an electromagnet inside the unit engages a locking mechanism that ties both side gears to the case, so 100 percent of the available torque goes to both rear tires equally in forward and reverse. The ELocker4 uses a 4-pinion net-forged gear set for strength under the higher torque of a full-size truck, and Eaton lists engagement at about 0.14 seconds on the direct-acting design. Because it is electric, it needs no air compressor or air lines, only the switch and wiring harness that come in the box.

Signs your Tundra needs a locker or new carrier

• One rear tire spins on loose climbs, in mud or on snow while the opposite tire does not move
• Traction control cutting power and the truck still getting stuck off road
• Clunk from the rear in tight turns or on and off throttle, from worn spider gears or cross shaft
• Metal on the fill-plug magnet or chipped spider gear teeth at a fluid change
• A ring and pinion swap already planned, which is the cheapest time to install a locker

How to confirm this is the right ELocker

Make sure your Tundra has the 10.5 inch rear with 36-spline axle shafts. Not every Tundra or Sequoia uses this axle; earlier and lighter applications use smaller Toyota rears with fewer splines, and those take the ELocker4 34-spline unit or the ELocker4 30-spline unit. Check the axle tag, measure the ring gear, or count the splines on a pulled shaft. This unit covers all ratios, so it works whether the truck has its factory gears or has been regeared for larger tires.

Fitment

Fits the 2007-2021 Toyota Tundra with the 10.5 inch rear axle and 36-spline axles, all gear ratios. Rear only. Toyota built many cab, bed, engine and drivetrain combinations in those years, so confirm the axle size and spline count on your truck before you order, or send us the year and VIN and we will verify it for you.

Install notes

Remove the axle shafts and the factory carrier, mark the bearing caps, and move the ring gear to the ELocker case with new bolts and thread locker. Revolution Gear lists starting values for the Toyota 10.5 inch of 0.048 inch pinion depth, 16-28 in-lb pinion bearing preload, 0.006-0.010 inch backlash, 145 ft-lb on the ring gear bolts and 150 ft-lb on the bearing caps. Fit new carrier bearings, set preload and backlash, and check the contact pattern. Route the coil wire through the housing as the instructions show, seal it, and mount the included rocker switch where you can reach it. Use a quality petroleum GL-5 gear oil; synthetic is acceptable if the axle maker allows it. A Yukon master overhaul kit for the Toyota 10.5 inch supplies the bearings, races, seal and shims for the job, and a bearing separator and puller set makes removing the old carrier bearings easier.

Does the ELocker4 14232-1 fit every 2007-2021 Tundra?

Only Tundras with the 10.5 inch rear and 36-spline axles. Check the axle size and count the shaft splines. Toyota rears with 30 or 34 spline shafts need a different ELocker.

Do I need to change my gear ratio to use it?

No. This unit is listed for all gear ratios, so it works with the factory gears or with a regear.

Is an air compressor needed?

No. The ELocker is electromagnetic. It comes with an Eaton locking rocker switch and wiring harness.

Can I drive on the street with it locked?

Use it locked only on loose or slick surfaces at low speed. On dry pavement leave it off so the axle can differentiate in turns; when off, it drives like an open differential.

What gear oil should I use?

Eaton recommends a quality petroleum GL-5 rated oil, with synthetic acceptable where the axle manufacturer allows. No friction modifier is needed since there are no clutch packs.

What else should I replace during the install?

New carrier bearings, ring gear bolts, the pinion seal and axle seals if they are weeping. A master overhaul kit covers most of it.