Eaton Detroit Truetrac Differential 32 Spline 1.38in Axle Shaft Diameter Rear Dana 44

A first-generation Nissan Titan that spins its inside rear tire pulling out of a wet driveway, or a 2005-2007 Frontier or Xterra with the big M226 rear that digs a hole with one wheel on a trail, is what the Eaton Detroit Truetrac 913A582 is built to fix. The listing reads "Rear Dana 44" because the Nissan M226 is a Dana 44 design; Eaton's own catalog names this part as the Truetrac for the Nissan M226 with 32-spline, 1.38 inch axle shafts, all ring gear ratios.

What the Truetrac does in an M226 rear

The Truetrac replaces the open carrier with a case full of helical pinion gears sitting in pockets. When one tire starts to lose grip, the gear separating forces push the pinions against the pocket walls, and that friction biases torque toward the tire that still has traction. There are no clutches, springs or air lines, so nothing wears out the way a clutch posi does, and it drives normally on the street with no chatter in parking lots. It works in forward and reverse. The one thing it cannot do is send torque to a tire that is fully off the ground, which is why trail rigs sometimes lightly drag the brakes to load it.

Symptoms that point to this unit

• One-tire peel on launch, wet grass or a boat ramp from the open rear
• Wanting traction for towing without adding clutches that need friction modifier
• A broken or noisy factory spider gear set found during a bearing or gear job
• A factory e-locker that no longer engages and that you would rather replace than repair

How to confirm before buying

Make sure the truck actually has the M226 rear: it is the larger rear axle on the Titan and the optional heavy rear on some Frontier and Xterra trims, while many Frontiers and Xterras came with a smaller Nissan rear. Check the axle tag or the build sheet, and count the axle splines if the shafts are out. If it is an e-locker axle, read the install note below before you order. Our Dana 44 problems and rebuild guide covers the noises worth chasing first, and the Detroit Locker vs Truetrac guide explains why a gear-type unit suits a daily-driven truck.

Fitment

Eaton's product selector lists 913A582 for the 2003-2007 Nissan Titan rear M226, the 2005-2007 Xterra with the M226 and manual transmission, and the 2005-2007 Frontier with the M226 option, all ratios. Eaton does not list 2008-and-newer trucks for this part, and the M226 parts catalogs split 2004-2007 and 2008-up versions, so if your Titan is 2008 or newer, send us the year and VIN before ordering. A leaking pinion seal on these trucks often means a grooved yoke, so check the 2004-2007 Titan rear pinion flange; other axle parts are in the hard parts section.

Install notes

• Eaton's catalog note: trucks with the OE electric locker option need axle shaft relief grinding for this carrier to fit properly. Plan for that before the truck is torn down.
• This is the moment to replace carrier and pinion bearings with the Titan rear master bearing kit or the Yukon M226 master overhaul kit.
• Carrier bearing preload is set with shims, so take careful notes on the original stack and recheck backlash and pattern with marking compound.
• The Truetrac needs no limited slip additive or friction modifier. Fill with a quality petroleum-based GL-5 gear oil in the grade your owner's manual calls for.
• Use new ring gear bolts with thread locker, and a new cover gasket or sealant.

Is this a Dana 44 or a Nissan part?

Both. The Nissan M226 rear is a Dana 44 design, and Eaton catalogs 913A582 as the Truetrac for the Nissan M226 with 32-spline shafts.

Does it fit my 2012 Titan?

Eaton's selector only lists it through 2007. 2008-up M226 parts are cataloged separately, so send us your year and VIN to confirm before ordering.

My Titan has the factory e-locker. Can I use this?

Yes, but Eaton notes that vehicles with the OE electric locker option need axle shaft relief grinding for this carrier to fit properly.

Do I need friction modifier?

No. The Truetrac is a helical gear unit with no clutches, so it runs on standard GL-5 gear oil without limited slip additive.

Does it work in reverse and with any gear ratio?

Yes. It works in forward and reverse, and Eaton lists it for all ratios in the M226.

What else should I replace with it?

Carrier and pinion bearings, the pinion seal and a crush sleeve or shims, using a Titan rear master bearing or overhaul kit.