Eaton Detroit Truetrac Differential 35 Spline 1.52in Axle Shaft Dia 3.73 & Down Ratio Rear Dana 80
The Dana 80 is the full-float rear axle under 1994-2002 Ram 3500s (and manual-trans or V10 2500s of the same years), 1999-2016 Ford F-350 dually pickups, many F-450s and the 1991-2002 GM C3500 HD. Most of those trucks left the factory with either an open case or a clutch-type Power-Lok or Trac-Lok that has long since worn out, so the truck spins one rear tire on a wet boat ramp or a snowy hill with a trailer on the ball. The Eaton Detroit Truetrac 915A567 is the gear-type limited slip for a Dana 80 with 35-spline shafts and gears of 3.73 or numerically lower.
Instead of clutch plates, the Truetrac uses helical side gears and sets of helical pinions that sit in pockets machined into the case. In normal driving it acts like an open differential, so the duallies track straight and turn without the scrub or tire chirp you get from a locker. When one tire loses grip, the thrust of the helical gears loads the pinions against their pockets, and that friction sends torque toward the tire that still has traction. Eaton describes the engagement as automatic, smooth and quiet, with no wear parts to service. On a Dana 80 that matters: the old OEM clutch packs are the part that fails, and this design has none to replace.
Make sure the axle is really a Dana 80. It has straight tubes, an asymmetrical 10-bolt cover and an "80" cast into the housing; a Dana 70 or Sterling 10.5 looks similar from a distance and takes a different carrier. Next, count the axle splines. Dana 80 shafts come in 35 and 37 spline, and this unit is 35 spline. Finally, read the ratio from the axle tag or count the ring and pinion teeth. Dana 80 carriers split between 3.73 and 4.10, so a truck with 3.54 or 3.73 gears takes this case, while 4.10 and deeper needs the 4.10-and-up version. Our carrier break explainer and Truetrac buyer's guide by axle and spline cover how to check. If you also hear bearing howl, read Dana 80 rear axle problems and rebuild cost first.
Per the listing and Revolution's spec block: Dana 80 rear, 35-spline axles (the listing lists a 1.52 in. shaft diameter), 3.73-and-down carrier break, Eaton part number 915A567. Dana 80 rears went into Ford, Ram and GM heavy-duty trucks for many years, so there is no single vehicle list. Match the housing, spline count and ratio, or send us your year and VIN and we will check it. Prefer a clutch-type posi? The Yukon Dura Grip for Dana 80 35-spline 3.73-down covers the same axle. Running 4.10s? See the Dura Grip 4.10-up. Every axle part we stock is in hard parts.
| Brand | Eaton |
| Part number | 915A567 |
| Fits | Eaton Detroit Truetrac Differential 35 Spline 1.52in Axle Shaft Dia 3.73 & Down Ratio Rear Dana 80 |
| Type | Differentials |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. This case is the 3.73-and-down carrier. Dana 80 ring and pinion sets of 4.10 and deeper mount on a different case, the 4.10-and-up carrier.
Not as-is. It is machined for 35-spline shafts. A 37-spline Dana 80 needs a 37-spline carrier, or you would have to change both axle shafts to 35 spline.
No. It has no clutch packs, and Eaton says friction modifier reduces its performance. Drain the old oil completely if the axle had a Trac-Lok with additive.
It drives like an open differential on pavement, so there is no clunking or pulling in turns. When one side loses grip on a ramp or wet lot, it biases torque to the side with traction automatically.
Carrier bearings at a minimum, and a full master bearing kit if the pinion bearings are original. Use new ring gear bolts and fresh GL-5 oil.
