DSE FN988 Assembled Center Section 3.55 Ratio REM Polished (070880-355DS-R)
Get the strength and packaging advantages of a Ford 9-inch housing with the efficiency and quieter operation of an 8.8-inch gearset with the Detroit Speed FN988 Assembled Center Section. Part number 070880-355DS-R combines Detroit Speed's patent-pending FN988 design with a 3.55 gear ratio, 31-spline Eaton Truetrac differential, and REM-polished ring and pinion. The complete assembly is designed to bolt directly into a Ford 9-inch housing while using an 8.8-inch gearset for a serious drivetrain upgrade built around strength, efficiency, and refined operation.
The FN988 is engineered well beyond a basic third-member assembly. A high-strength nodular cast iron case is paired with forged alloy steel carrier bearing caps, premium ring and pinion, ARP ring gear bolts with safety wire, a solid pinion preload spacer, and a 1350 forged steel pinion yoke with U-bolt kit. Internal oil channels continuously lubricate the pinion bearings, while threaded jack bolt holes in the mounting flange help simplify removal of the case from the axle housing. This version adds REM-polished gears, which use a surface-finishing process designed to reduce friction and heat while improving oil retention, component life, and quiet, efficient operation.
Specifications
- Part Number: 070880-355DS-R
- Product Type: Differential Assembly
- Case Series: FN988
- Gear Ratio: 3.55
- Differential: 31-Spline Eaton Truetrac
- Axle Shaft Spline Quantity: 31
- Carrier Style: Ford 8.8-inch
- Case Material: Nodular Iron
- Yoke Style: 1350
- REM-Polished Gears: Yes
- Universal Ford 9-inch Center Section: Yes
- Application Specific: No
Features
- Patent-pending FN988 design uses an 8.8-inch gearset inside a Ford 9-inch housing
- Engineered for quieter and more efficient operation than conventional 9-inch components
- 3.55 gear ratio provides a versatile balance for performance-oriented street and track builds
- 31-spline Eaton Truetrac differential delivers proven limited-slip performance
- REM-polished ring and pinion help reduce friction and heat while promoting improved oil retention
- High-strength nodular cast iron case provides a durable foundation for high-performance use
- Forged alloy steel carrier bearing caps add strength where drivetrain loads demand it
- Premium ring and pinion uses ARP ring gear bolts secured with safety wire
- Internal oil channels provide continuous lubrication to the pinion bearings
- Solid pinion preload spacer supports consistent pinion bearing setup
- 1350 forged steel pinion yoke includes a U-bolt kit
- Threaded jack bolt holes in the mounting flange help make case removal easier
- Case incorporates mounting holes for bolt-on accessories
- FN988 case is compatible with 8.8-inch gears, differentials, and spools
Installation Notes
This FN988 center section is a universal Ford 9-inch center section and is not assigned to a specific year, make, or model. FN988-specific axle shafts are required, and the driveshaft will need to be shortened for installation. Verify the complete rear axle and driveline configuration before ordering.
FAQs
What makes the FN988 different from a conventional Ford 9-inch center section?
The FN988 is designed to install in a Ford 9-inch housing while using an 8.8-inch gearset. This allows the assembly to combine the desirable packaging of the 9-inch housing with a gear design engineered for quieter and more efficient operation.
What does REM polishing do to the gears?
REM treatment produces a smooth micro-textured gear surface intended to improve oil retention while reducing friction and heat. The process can contribute to quieter operation and increased component life.
Can 070880-355DS-R be installed with standard Ford 9-inch axles?
No. Detroit Speed specifies that FN988-specific axle shafts are required. The driveshaft must also be shortened as part of the installation.
Why Buy from Beefcake Racing?
Beefcake Racing specializes in performance drivetrain, suspension, and chassis components for serious street, strip, autocross, and track builds. Need help confirming whether this Detroit Speed FN988 center section is right for your rear axle combination? Contact our experienced sales team before ordering. Email sales@beefcakeracing.com or call 1-855-827-7223 for assistance.
CA Residents: WARNING: Cancer and Reproductive Harm www.P65Warnings.ca.gov
