Availability
Complete Third Member and Center Sections
Instead of piecing one together and hoping it all fits, get a complete third member assembly with one part number from Summit Racing Equipment!
A complete third member...
Instead of piecing one together and hoping it all fits, get a complete third member assembly with one part number from Summit Racing Equipment!
A complete third member assembly (sometimes called a center section) includes everything you need to connect your driveshaft to your rear axles. They typically include a U-joint style yoke to connect to your driveshaft, ring and pinion gears, differential carrier, and a case. They’re also available with spools for maximum traction.
Whether you need a lightweight center section for racing, a trail-tough third member assembly for off-roading, or a stock replacement for fixing up your...
Instead of piecing one together and hoping it all fits, get a complete third member assembly with one part number from Summit Racing Equipment!
A complete third member assembly (sometimes called a center section) includes everything you need to connect your driveshaft to your rear axles. They typically include a U-joint style yoke to connect to your driveshaft, ring and pinion gears, differential carrier, and a case. They’re also available with spools for maximum traction.
Whether you need a lightweight center section for racing, a trail-tough third member assembly for off-roading, or a stock replacement for fixing up your daily driver, our search tools make it easy to find the right third member assembly! For example, if you’re your looking for a Ford 9 inch third member, you can filter by case style (Ford, Chevy, Toyota, etc.), axle spline count, gear ratio, and more! With hundreds of applications available, Summit is your go-to source for complete third member assemblies.
Differential Identification Charts
Not sure what you’ve got back there? Visit Summit’s Help Center for our rear-end identification guides.
Even More Complete!
Need the matching axles, too? Consider a complete rear end assembly!
Top Brands
No third party resellers here—Summit Racing only partners with trusted manufacturers like Moser, Strange Engineering, Trail Gear, and Currie Enterprises.
Third Member Complete Assembly, Ford 9 in., 3.50:1 Gear Ratio, TwinTrac, 31-Spline, Nodular Iron Case, Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9CT350S50
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
Third Member, 3.70:1 Gear Ratio, Currie TwinTrac, 31-Spline, Nodular Iron Case, Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9CT370S50
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
Third Member, 4.11:1 Gear Ratio, Currie TwinTrac, 31-Spline, Nodular Iron Case, Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9CT411S50
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
Third Member, 3.89:1 Gear Ratio, Currie TwinTrac, 31-Spline, Nodular Iron Case, Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9CT389S50
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
Center Section, 9 in. Ford, Nodular Iron, Trak-Lok, 31-Spline Axle, 3.70:1 Ratio, Each
Part Number: MSR-3MNC31AN370
Not Yet Reviewed
Estimated Ship Date: Apr 14, 2026 if ordered today
Estimated Ship Date: Apr 14, 2026 if ordered today
Need It Sooner? We recommend these similar substitute parts:
FN988 TA CASE 31 SPL TT 3.31 RATIO 1350
Part Number: DSR-070881-331DS
Not Yet Reviewed
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
CURRIE SUPER SPORTSMAN THIRD MEMBER - 3.70 GEARS - 31 SPLINE CURRIE TWINTRAC - ALUMINUM DAYTONA PINION SUPPORT - 1350 CHROMOLY YOKE
Part Number: CUR-CE9CT370SS50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
Third Member Complete Assembly, Detroit Speed, FN988 Assembly, 8.8 in. Gears, 31 Spline, Truetrac, 3.55 Ratio, 1350 Yoke, for Ford 9 in Housing, Each
Part Number: DSR-070880-355DS
Not Yet Reviewed
Estimated Ship Date: Mar 31, 2026 if ordered today
Estimated Ship Date: Mar 31, 2026 if ordered today
CURRIE SUPER SPORTSMAN THIRD MEMBER - 3.25 GEARS - 31 SPLINE CURRIE TWINTRAC - ALUMINUM DAYTONA PINION SUPPORT - 1350 CHROMOLY YOKE
Part Number: CUR-CE9CT325SS50
Not Yet Reviewed
Estimated Ship Date: Apr 13, 2026 if ordered today
Estimated Ship Date: Apr 13, 2026 if ordered today
THIRD MEMBER ASSEMBLY
Part Number: CUR-CE-9CT325S50
Not Yet Reviewed
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
CURRIE PRO THIRD MEMBER - 3.25 GEARS - 35 SPLINE TRUETRAC - ALUMINUM DAYTONA PINION SUPPORT - 1350 CHROMOLY YOKE
Part Number: CUR-CE9TT325R50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 35-Spline, Aluminum Case, Aluminum Main Cap, Bolt Retention, 4.11:1 Ratio, 1350 Series Yoke, Each
Part Number: MSR-3MAS35AT411P
Not Yet Reviewed
Estimated Ship Date: Apr 3, 2026 if ordered today
Estimated Ship Date: Apr 3, 2026 if ordered today
CURRIE SUPER SPORTSMAN THIRD MEMBER - 3.00 GEARS - 31 SPLINE CURRIE TWINTRAC - ALUMINUM DAYTONA PINION SUPPORT - 1350 CHROMOLY YOKE
Part Number: CUR-CE9CT300SS50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
Complete Third Member, 3.50:1 Gear Ratio, Detroit TrueTrac, 35-Spline, Nodular Iron Race Case, Aluminum Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9TT350R50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
Complete Third Member, 4.11:1 Gear Ratio, Detroit TrueTrac, 35-Spline, Nodular Iron Race Case, Aluminum Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9TT411R50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
Third Member, 3.00:1 Gear Ratio, Currie TwinTrac, 31-Spline, Nodular Iron Case, Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9CT300S50
Not Yet Reviewed
Estimated Ship Date: Apr 13, 2026 if ordered today
Estimated Ship Date: Apr 13, 2026 if ordered today
Third Member Complete Assembly, Detroit Speed, FN988 Assembly, 8.8 in. Gears, 31 Spline, Truetrac, 3.73 Ratio, 1350 Yoke, for Ford 9 in Housing, Each
Part Number: DSR-070880-373DS
Not Yet Reviewed
Estimated Ship Date: Mar 27, 2026 if ordered today
Estimated Ship Date: Mar 27, 2026 if ordered today
Third Member Complete Assembly, Detroit Speed, FN988 Assembly, 8.8 in. Gears, 31 Spline, Truetrac, 3.31 Ratio, 1350 Yoke, for Ford 9 in Housing, Each
Part Number: DSR-070880-331DS
Estimated Ship Date: Tomorrow if ordered today
Estimated Ship Date: Tomorrow if ordered today
CURRIE SUPER SPORTSMAN THIRD MEMBER - 3.50 GEARS - 31 SPLINE CURRIE TWINTRAC - ALUMINUM DAYTONA PINION SUPPORT - 1350 CHROMOLY YOKE
Part Number: CUR-CE9CT350SS50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
Third Member Complete Assembly, Detroit Speed, FN988 Assembly, 8.8 in. Gears, 31 Spline, Truetrac, 3.08 Ratio, 1350 Yoke, for Ford 9 in Housing, Each
Part Number: DSR-070880-308DS
Not Yet Reviewed
Estimated Ship Date: Mar 27, 2026 if ordered today
Estimated Ship Date: Mar 27, 2026 if ordered today
Center Section, 9 in. Ford, Nodular Iron Case, Truetrac, 35-Spline, Daytona Pro/Street Support, 3.70:1, Each
Part Number: MSR-3MNT35AA370
Not Yet Reviewed
Estimated Ship Date: Apr 3, 2026 if ordered today
Estimated Ship Date: Apr 3, 2026 if ordered today
Center Section, 9 in. Ford, Nodular Iron Case, Trac-Lok, 31-Spline, Daytona Pro/Street Support, 3.50:1, Each
Part Number: MSR-3MNC31AN350
Not Yet Reviewed
Estimated Ship Date: Apr 3, 2026 if ordered today
Estimated Ship Date: Apr 3, 2026 if ordered today
Complete Third Member, 3.70:1 Gear Ratio, Detroit TrueTrac, 35-Spline, Nodular Iron Race Case, Aluminum Big Bearing Pinion Support, 1350 Yoke, Each
Part Number: CUR-CE-9TT370R50
Not Yet Reviewed
Estimated Ship Date: Apr 29, 2026 if ordered today
Estimated Ship Date: Apr 29, 2026 if ordered today
FORD 9'' 3.50 N GEAR 31 SPLINE TRUETRAC
Part Number: DSR-90-20015
Not Yet Reviewed
Estimated Ship Date: Apr 7, 2026 if ordered today
Estimated Ship Date: Apr 7, 2026 if ordered today
Center Section, 9 in. Ford, Aluminum Case, Spool, 35-Spline Axle, Pro 10-Hole Support, 4.86:1 Ratio, Each
Part Number: MSR-3MAS35AT486P
Not Yet Reviewed
Estimated Ship Date: Apr 3, 2026 if ordered today
Estimated Ship Date: Apr 3, 2026 if ordered today
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