DSE FN988 Assembled Center Section - 3.08 Ratio / 31-Spline Truetrac - 070880-308DS
Get the strength and packaging advantages of a traditional Ford 9-inch housing with the quieter, more efficient operation of an 8.8-inch gearset with the Detroit Speed 070880-308DS FN988 Assembled Center Section. This patent-pending Detroit Speed design bolts into a traditional Ford 9-inch housing while using an 8.8-inch ring and pinion, giving performance builders a purpose-engineered alternative to the gear noise and efficiency losses commonly associated with conventional 9-inch center sections. This version comes completely assembled with a 3.08 gear ratio, 31-spline Eaton Truetrac differential, and 1350 forged-steel pinion yoke with U-bolts.
Detroit Speed engineered the FN988 for serious performance, starting with a high-strength nodular cast iron case and forged alloy-steel carrier bearing caps. The premium ring and pinion uses ARP ring bolts with safety wire, while a solid pinion preload spacer adds another performance-focused detail to the assembly. Internal oil channels continuously lubricate the pinion bearings, and threaded jack-bolt holes in the mounting flange help make future removal from the axle housing easier. The case also incorporates mounting holes for bolt-on accessories. Designed and engineered by Detroit Speed and made in the USA, the 070880-308DS combines proven 8.8-inch differential components with a package designed to install in a traditional 9-inch housing.
Specifications
- Manufacturer: Detroit Speed
- Part Number: 070880-308DS
- Product Type: Differential Assembly
- Case Series: FN988
- Case Material: Nodular Iron
- Carrier Style: Ford 8.8-inch
- Differential: Eaton Truetrac
- Axle Shaft Spline Quantity: 31
- Gear Ratio: 3.08
- Yoke Style: 1350
- Pinion Yoke: Forged Steel
- Yoke Hardware: U-Bolt Kit
- REM Polished: No
- Universal 9-Inch Center Section: Yes
- Application Specific: No
- Emissions Code: 4
- Manufacturing: Designed and engineered by Detroit Speed and made in USA
Features
- Patent-pending FN988 design combines an 8.8-inch gearset with compatibility for a traditional Ford 9-inch housing
- Designed for quieter and more efficient operation than standard 9-inch components
- 3.08 gear ratio
- 31-spline Eaton Truetrac 8.8-inch differential
- High-strength nodular cast iron case
- Premium ring and pinion with ARP ring bolts and safety wire
- Internal oil channels provide continuous lubrication to the pinion bearings
- Solid pinion preload spacer
- Forged alloy-steel carrier bearing caps
- 1350 forged-steel pinion yoke with U-bolt kit
- Threaded jack-bolt holes in the mounting flange help ease removal from the axle housing
- Case includes mounting holes for bolt-on accessories
- FN988 case is compatible with 8.8-inch gears, differentials, and spools
- Designed and engineered by Detroit Speed
- Made in USA
Fitment Notes
The Detroit Speed 070880-308DS is a universal FN988 center section and is not assigned to a specific year, make, or model. It is designed to bolt into a traditional Ford 9-inch housing. FN988-specific axle shafts are required, and the driveshaft will typically need to be shortened because of the FN988's forward pinion location. Verify the complete rear axle and driveline combination before installation.
FAQs
What makes the Detroit Speed FN988 different from a traditional Ford 9-inch center section?
The FN988 is designed to bolt into a traditional Ford 9-inch housing while using an 8.8-inch gearset. Detroit Speed developed this combination to provide quieter, more efficient operation while retaining the packaging advantages of the 9-inch housing.
What differential and gear ratio are included with 070880-308DS?
Part number 070880-308DS is assembled with a 31-spline Eaton Truetrac differential and a 3.08 gear ratio. It also includes a 1350 forged-steel pinion yoke with a U-bolt kit.
Can I install the FN988 with standard Ford 9-inch axle shafts?
No. Detroit Speed specifies that FN988-specific axle shafts are required. The driveshaft will also typically need to be shortened because the FN988 uses a forward pinion location.
Why Buy Detroit Speed from Beefcake Racing?
Beefcake Racing is your source for Detroit Speed rear axle, suspension, chassis, and drivetrain components for serious street, pro-touring, autocross, and track builds. Building an FN988 rear end requires matching the center section with the correct axle shafts and driveline components, and our team can help you put together the right combination. Questions about Detroit Speed 070880-308DS or your FN988 rear axle setup? Email sales@beefcakeracing.com or call 1-855-827-7223.
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