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SKU: 912A587
Eaton Detroit Truetrac Differential – 28 Spline, 1.20" Axle Shaft Diameter, Rear 9" (Ford)
The Eaton Detroit Truetrac Differential (912A587) is a helical-gear style, limited-slip differential designed for the Rear 9" Ford axle with 28 spline axles and 1.20" axle shaft diameter. It maximizes wheel traction by automatically transferring torque to the wheel with the most grip, improving acceleration, cornering, and overall driving performance. Unlike traditional clutch-type limited-slip differentials, the Truetrac is maintenance-free, operates smoothly in both forward and reverse, and requires no special fluids or additives. Its robust helical-gear design provides reliable, automatic operation without the chatter or engagement issues common with other limited-slip units. This makes the Detroit Truetrac an excellent choice for street, strip, or off-road applications where consistent traction and durability are essential.
Key Features
- Helical-Gear Limited-Slip Design – Automatically transfers torque to the wheel with the most traction
- Maintenance-Free Operation – No clutches to wear out, no special fluids required
- Smooth & Quiet – Operates seamlessly in forward and reverse without chatter
- 28 Spline, 1.20" Axle Shaft Diameter – Direct fit for Rear 9" Ford axles
- Versatile Application – Ideal for street, performance, and off-road use
Specs
| Spec | Detail |
|---|---|
| Part Number | 912A587 |
| Brand | Eaton Detroit Truetrac |
| Type | Helical-Gear Limited-Slip Differential |
| Compatibility | Rear 9" Ford axle with 28 spline axles and 1.20" axle shaft diameter |
| Spline Count | 28 |
| Axle Shaft Diameter | 1.20 inches |
| Country of Origin | United States |
| Warranty | Eaton Limited Warranty |
Whats Included
- Detroit Truetrac Differential Assembly
- Installation instructions
Product Notes
- Designed for Rear 9" Ford axles with 28 spline axles and 1.20" shaft diameter
- Provides automatic traction improvement without the maintenance of clutch-style units
- Professional installation with proper setup and gear oil is highly recommended
Installation Notes
- Requires differential disassembly and professional installation
- Estimated time: Several hours (full differential rebuild recommended)
- Use the correct limited-slip gear oil additive if specified by the vehicle manufacturer
This Part Fits
| Year Range | Make | Model | Notes |
|---|---|---|---|
| Various | Ford | Models with Rear 9" Axle | 28 Spline, 1.20" Axle Shaft Diameter |
Why Choose Eaton Detroit Truetrac Differentials?
- Helical-gear design provides smooth, automatic traction without clutches or maintenance
- Reliable performance in street, strip, and off-road applications
- Trusted by enthusiasts and professional builders for decades
Frequently Asked Questions
-
Q: Is this differential a direct replacement for my stock unit?
A: It is a direct drop-in for Rear 9" Ford axles with 28 spline axles and 1.20" shaft diameter, but professional installation and setup are required. -
Q: Does it require special fluid?
A: Use a high-quality limited-slip gear oil. Some applications may require an additive – check your vehicle’s specifications. -
Q: Is professional installation required?
A: Yes – differential work requires specialized tools, knowledge, and proper setup for safety and performance.
Shipping & Handling
- Method: Ground UPS or FedEx (oversize shipping may apply)
- Availability: In stock – ships same or next business day
- Packaging: Secure Eaton retail packaging
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