Eaton 912A569 Detroit Truetrac Limited Slip for 1984-2009 Jeep/Dana 35 Rear 27-S

Product Description

The Eaton 912A569 Detroit Truetrac is a robust helical‑gear limited slip differential designed for Dana 35 rear axles, engineered to significantly improve traction while maintaining smooth, quiet operation. With a 27‑spline shaft, a 1.18‑inch axle diameter, and support for ring gear ratios of 3.54 and higher, it's ideal for Jeep owners who want dependable performance -- especially in trail, street, or mixed use. The Truetrac design eliminates clutch packs or frictions plates, choosing instead an all‑gear solution that requires little maintenance and provides torque bias automatically when one wheel loses grip.

Fitment is confirmed for many Jeep models from 1984 through approximately 2009 using the rear Dana 35 with 27 splines. If your vehicle has that axle, this part bolts in using the original housing and gears (provided the gear ratio meets the minimum). Be sure to verify your axle is Dana 35, count the splines, measure the axle shaft diameter, and check ring gear ratio before ordering. Installation involves removal of the existing carrier, setting proper backlash and preload per OEM specs, torquing bolts to correct values, and using the correct gear oil (no limited slip additives required). Fitment beyond 2009 is unconfirmed.

Vehicle Fitment

• 1984–2001 Jeep Cherokee (Rear Dana 35, 27‑Spline, 3.54 & Up)
• 1986–1992 Jeep Comanche (Rear Dana 35, 27‑Spline, 3.54 & Up)
• 1993–2004 Jeep Grand Cherokee (Rear Dana 35, 27‑Spline, 3.54 & Up)
• 1987–1995 Jeep Wrangler YJ (Rear Dana 35, 27‑Spline, 3.54 & Up)
• 1997–2006 Jeep Wrangler TJ (Rear Dana 35, 27‑Spline, 3.54 & Up)
• 2002–2003 Jeep Liberty (Rear Dana 35, 27‑Spline, 3.54 & Up)

Fitment Notes

• Only fits rear differentials with a **Dana 35**, **27‑spline** axle shafts. 
• Axle shaft diameter ~ **1.18 in**. 
• Ring gear must be **3.54 or numerically higher**; lower gear ratios are not supported. 
• Fits both **C‑clip** and **non C‑clip** Dana 35 rear housings. 
• Cover bolt pattern: 10‑bolt differential cover (common Dana 35 type). 
• Fitment confirmed through 2009; no verified official listing beyond that.

Features

• Helical‑gear limited slip differential (Detroit Truetrac design) for smooth, automatic torque biasing. 
• Works in both forward and reverse; no driver input needed. 
• No clutch packs or wearable friction plates--maintenance‑free under normal use. 
• Quiet and smooth operation even under load or when wheels slip. 
• Supports a wide range of gear ratios--3.54 up through 5.13 (depending on application). {index=10}
• Strong steel construction built for durability in off‑road, trail, and towing conditions. 
• Fits both lighter duty and heavier duty Dana 35 rear ends (C‑clip or non C‑clip). 
• Compatible with restoration, street, muscle, and off‑road builds. 

Specifications

• Part Number: **912A569** (Detroit Truetrac, Eaton) 
• Ring Gear Size: ~ **7.56 inches** 
• Spline Count: **27 splines** 
• Axle Shaft Diameter: approx **1.18 in (≈30.0 mm)** 
• Supported Gear Ratios: **3.54 & up** (numerically higher) 
• Axle Location: Rear differential (Dana 35) 
• Weight: ~ **18.7 lb** 
• Differential Type: Limited Slip Differential – all‑gear helical (Truetrac) 
• Cover Bolt Pattern: 10‑bolt (Dana 35) rear cover. 

Included Components

• 1x Eaton Detroit Truetrac differential carrier assembly (pre‑assembled, sealed, with helical internals) 
• Note: Ring & pinion gears, cover, gasket/seal, mounting hardware generally **not included** -- verify with vendor.