Eaton Detroit Truetrac Differential, 29-Spline, Rear AMC 20, Part Number 912A579

The Detroit Truetrac is a helical-gear style, limited-slip differential that maximizes wheel traction and enhances driving characteristics. Maintenance-free, it features smooth, automatic operation in forward and reverse. Its versatility makes Detroit Truetrac the ideal traction solution for almost any type of vehicle. Detroit Truetrac® Differential; 29 Spline; 1.27 in. Axle Shaft Diameter; 3.08 And Up Ring Gear Pinion Ratio; Rear AMC 20;

• Optimized Torque Bias Ratios Deliver Max Acceleration And Handling
• No Special Lubrication Or Friction Modifiers Needed
• Helical Gear Limited Slip Differential
• Durable; Smooth; Quiet Operation
• Works In Forward And Reverse
• Ideal For Most Vehicles
• Automatic Engagement

The Eaton Detroit Truetrac differential is a helical-gear limited-slip differential designed to improve traction, acceleration, and handling for vehicles equipped with a rear AMC 20 axle. Its automatic operation helps transfer torque to the wheel with available grip, supporting more consistent performance on changing road surfaces without requiring driver input.

Designed for applications with 29-spline axle shafts, a 1.27-inch axle shaft diameter, and ring gear and pinion ratios of 3.08 and numerically higher, the Eaton Detroit Truetrac provides smooth engagement in both forward and reverse. Its gear-driven design operates without clutch packs, helping deliver durable, quiet performance with minimal maintenance requirements.

• Application: Rear AMC 20 axle assemblies
• Axle Spline Count: 29 spline
• Axle Shaft Diameter: 1.27 inches
• Compatible Gear Ratio: 3.08 and numerically higher
• Differential Type: Helical-gear limited-slip differential
• Operation: Automatic engagement in forward and reverse
• Lubrication Requirement: No special lubricant or friction modifier required
• Torque Biasing: Optimized torque bias ratios for improved acceleration and handling

The Eaton Detroit Truetrac, part number 912A579, is engineered for drivers seeking dependable traction enhancement without the complexity of an electronically controlled or clutch-type limited-slip system. It is suitable for a wide range of street, utility, and off-road vehicle applications when axle compatibility is confirmed.

Fitment includes select 1984–1986 Jeep Wagoneer and Jeep Cherokee applications equipped with the specified rear AMC 20 axle configuration. Verify axle type, spline count, shaft diameter, and gear ratio before installation.

What's Included: One Eaton Detroit Truetrac differential.

Features:

• Optimized torque bias ratios improve acceleration and handling
• Helical-gear limited-slip design provides automatic traction control
• No special lubrication or friction modifiers required
• Smooth, quiet, and durable operation
• Operates automatically in forward and reverse
• Designed for rear AMC 20 applications
• Compatible with 29-spline axle shafts
• Supports 3.08 and numerically higher ring gear and pinion ratios

Fitments:
1976 Jeep Cherokee Base
1976 Jeep Cherokee S
1976 Jeep CJ5 Base
1976 Jeep CJ5 Renegade
1976 Jeep CJ7 Base
1976 Jeep CJ7 Renegade
1976 Jeep Wagoneer Base
1976 Jeep Wagoneer Custom
1977 Jeep Cherokee Base
1977 Jeep Cherokee S
1977 Jeep CJ5 Base
1977 Jeep CJ5 Golden Eagle
1977 Jeep CJ5 Renegade
1977 Jeep CJ7 Base
1977 Jeep CJ7 Golden Eagle
1977 Jeep CJ7 Renegade
1977 Jeep Wagoneer Base
1978 Jeep Cherokee Base
1978 Jeep Cherokee Wide Track
1978 Jeep CJ5 Base
1978 Jeep CJ5 Golden Eagle
1978 Jeep CJ5 Renegade
1978 Jeep CJ7 Base
1978 Jeep CJ7 Golden Eagle
1978 Jeep CJ7 Renegade
1978 Jeep Wagoneer Base
1979 Jeep Cherokee Base
1979 Jeep Cherokee Wide Track
1979 Jeep CJ5 Base
1979 Jeep CJ5 Golden Eagle
1979 Jeep CJ5 Renegade
1979 Jeep CJ7 Base
1979 Jeep CJ7 Golden Eagle
1979 Jeep CJ7 Renegade
1979 Jeep Wagoneer Base
1979 Jeep Wagoneer Limited
1980 Jeep Cherokee Base
1980 Jeep Cherokee Wide Track
1980 Jeep CJ5 Base
1980 Jeep CJ5 Golden Eagle
1980 Jeep CJ5 Laredo
1980 Jeep CJ5 Renegade
1980 Jeep CJ7 Base
1980 Jeep CJ7 Golden Hawk
1980 Jeep CJ7 Laredo
1980 Jeep CJ7 Renegade
1980 Jeep Wagoneer Base
1980 Jeep Wagoneer Limited
1981 Jeep Cherokee Base
1981 Jeep Cherokee Chief
1981 Jeep CJ5 Base
1981 Jeep CJ5 Laredo
1981 Jeep CJ5 Renegade
1981 Jeep CJ7 Base
1981 Jeep CJ7 Laredo
1981 Jeep CJ7 Renegade
1981 Jeep Scrambler Base
1981 Jeep Wagoneer Base
1981 Jeep Wagoneer Limited
1982 Jeep Cherokee Base
1982 Jeep Cherokee Chief
1982 Jeep CJ5 Base
1982 Jeep CJ5 Laredo
1982 Jeep CJ5 Limited
1982 Jeep CJ5 Renegade
1982 Jeep CJ7 Base
1982 Jeep CJ7 Laredo
1982 Jeep CJ7 Limited
1982 Jeep CJ7 Renegade
1982 Jeep Scrambler Base
1982 Jeep Scrambler SL
1982 Jeep Scrambler SR
1982 Jeep Wagoneer Base
1982 Jeep Wagoneer Brougham
1982 Jeep Wagoneer Limited
1983 Jeep Cherokee Base
1983 Jeep Cherokee Pioneer
1983 Jeep Cherokee Wide Track Chief
1983 Jeep CJ5 Base
1983 Jeep CJ5 Laredo
1983 Jeep CJ5 Limited
1983 Jeep CJ5 Renegade
1983 Jeep CJ7 Base
1983 Jeep CJ7 Laredo
1983 Jeep CJ7 Limited
1983 Jeep CJ7 Renegade
1983 Jeep Scrambler Base
1983 Jeep Scrambler SL
1983 Jeep Scrambler SR
1983 Jeep Wagoneer Brougham
1983 Jeep Wagoneer Limited
1984 Jeep Cherokee Base
1984 Jeep CJ7 Base
1984 Jeep CJ7 Renegade
1984 Jeep Grand Wagoneer Base
1984 Jeep Grand Wagoneer Limited
1984 Jeep Scrambler Base
1984 Jeep Scrambler SR
1984 Jeep Wagoneer Base
1984 Jeep Wagoneer Limited
1985 Jeep Cherokee Base
1985 Jeep Cherokee Chief
1985 Jeep Cherokee Laredo
1985 Jeep Cherokee Pioneer
1985 Jeep CJ7 Base
1985 Jeep CJ7 Laredo
1985 Jeep CJ7 Renegade
1985 Jeep Grand Wagoneer Base
1985 Jeep Grand Wagoneer Limited
1985 Jeep Scrambler Base
1985 Jeep Scrambler Laredo
1985 Jeep Scrambler Renegade
1985 Jeep Wagoneer Base
1985 Jeep Wagoneer Limited
1986 Jeep Cherokee Base
1986 Jeep Cherokee Chief
1986 Jeep Cherokee Laredo
1986 Jeep Cherokee Pioneer
1986 Jeep CJ7 Base
1986 Jeep CJ7 Laredo
1986 Jeep CJ7 Renegade
1986 Jeep Grand Wagoneer Base
1986 Jeep Wagoneer Base
1986 Jeep Wagoneer Limited
2003 Hummer H1 Base
2003 Hummer H2 Base
2004 Hummer H1 Base
2004 Hummer H2 Base
2005 Hummer H2 Base
2006 Hummer H1 Alpha
2006 Hummer H2 Base
2006 Hummer H3 Base
2007 Hummer H2 Base
2007 Hummer H3 Base
2007 Hummer H3 X
2008 Hummer H2 Base
2008 Hummer H3 Alpha
2008 Hummer H3 Base
2008 Hummer H3 X
2009 Hummer H2 Base
2009 Hummer H3 Alpha
2009 Hummer H3 Base
2009 Hummer H3 Championship Series
2009 Hummer H3 X

Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Unknown
Part Type: automotive
Epa: N/A
Carb Acknowledgement Required: false
Regular Stock: t
Units Per Sku: 1