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!

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.

Individual Parts

Part Groups

Results 1 - 25 of 779

Currie 9 in. Third Members CE-9CT370S50

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

5.0 out of 5 stars ( 2 )

Estimated Ship Date: Tuesday 9/2/2025

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Estimated Ship Date: Tuesday 9/2/2025

Currie 9 in. Third Members CE-9CT350S50

Third Member, 3.50:1 Gear Ratio, Currie TwinTrac, 31-Spline, Nodular Iron Case, Big Bearing Pinion Support, 1350 Yoke, Each

Part Number: CUR-CE-9CT350S50

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Tuesday 9/2/2025

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Estimated Ship Date: Tuesday 9/2/2025

Currie 9 in. Third Members CE-9CT411S50

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

3.0 out of 5 stars ( 1 )

Estimated Ship Date: Tuesday 9/2/2025

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Estimated Ship Date: Tuesday 9/2/2025

Currie 9 in. Third Members CE-9CT389S50

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

Not Yet Reviewed

Estimated Ship Date: Tuesday 9/2/2025

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Estimated Ship Date: Tuesday 9/2/2025

Detroit Speed FN988 Assembled Center Sections 070880-373DS

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: Tuesday 9/2/2025

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Estimated Ship Date: Tuesday 9/2/2025

Currie 9 in. Third Members CE-9TT350R50

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: Sep 24, 2025 if ordered today

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Estimated Ship Date: Sep 24, 2025 if ordered today

Currie 9 in. Third Members CE-9TT411R50

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: Sep 24, 2025 if ordered today

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Estimated Ship Date: Sep 24, 2025 if ordered today

Detroit Speed Inc Third Member Complete Assembly 070880-331DS

3RD MEMBER ASSEMBLY 3.31

Part Number: DSR-070880-331DS

4.0 out of 5 stars ( 1 )

Estimated Ship Date: Sep 8, 2025 if ordered today

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Estimated Ship Date: Sep 8, 2025 if ordered today

Currie 9 in. Third Members CE-9CT300S50

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: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Yukon Gear & Axle Third Member Complete Assembly YDAF9-350SVO-31

DROPOUT ASSEMBLY

Part Number: YGA-13210

Not Yet Reviewed

Estimated Ship Date: Sep 4, 2025 if ordered today

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Estimated Ship Date: Sep 4, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MNC31AN370

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: Tuesday 9/2/2025

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Estimated Ship Date: Tuesday 9/2/2025

Currie 9 in. Third Members CE-9CT325S50

THIRD MEMBER ASSEMBLY

Part Number: CUR-CE-9CT325S50

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Detroit Speed FN988 Assembled Center Sections 070880-355DS

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: Sep 15, 2025 if ordered today

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Estimated Ship Date: Sep 15, 2025 if ordered today

Detroit Speed FN988 Assembled Center Sections 070880-308DS

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: Sep 9, 2025 if ordered today

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Estimated Ship Date: Sep 9, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MNL35AA350

Center Section, 9 in. Ford, Nodular Iron, Locker, 35-Spline Axle, 3.50:1 Ratio, Each

Part Number: MSR-3MNL35AA350

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Currie 9 in. Third Members CE-9TT370R50

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: Sep 24, 2025 if ordered today

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Estimated Ship Date: Sep 24, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MNC31AN350

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: Sep 24, 2025 if ordered today

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Estimated Ship Date: Sep 24, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MNS40-AA529

Center Section, 9 in. Ford, Nodular Iron, Spool, 40-Spline Axle, 5.29:1 Ratio, Each

Part Number: MSR-3MNS40-AA529

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MSC28AN350

Center Section, 9 in. Ford, Nodular Iron Case, Trak-Lok, 28-Spline, Daytona Pro/Street Support, 3.50:1, Each

Part Number: MSR-3MSC28AN350

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Trail-Gear Assembled Super Finish Third Members 304633-1-KIT

Third Member Complete Assembly, Assembled 29-Spline Super Finish 3rd Members For Toyota 8" Axles- V6 5.29 ARB

Part Number: TGI-304633-1-KIT

Not Yet Reviewed

Estimated Ship Date: Oct 3, 2025 if ordered today

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Estimated Ship Date: Oct 3, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MAS35AA514P

Third Member Complete Assembly, Ford 9 in., 35-Spline, Aluminum Case, Aluminum Main Cap, Bolt Retention, 5.14:1 Ratio, 1350 Series Yoke, Each

Part Number: MSR-3MAS35AA514P

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MAT31AA370

Center Section, 9 in. Ford, Aluminum, Detroit Truetrac, 31-Spline Axle, 3.70:1 Ratio, Each

Part Number: MSR-3MAT31AA370

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Detroit Speed Inc Third Member Complete Assembly 90-30020

FORD 9'' 3.70 S GEAR 31 SPLINE TRUETRAC

Part Number: DSR-90-30020

Not Yet Reviewed

Estimated Ship Date: Sep 9, 2025 if ordered today

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Estimated Ship Date: Sep 9, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MAS35AT486P

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: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MAT31BA411

Center Section, 9 in. Ford, Aluminum, Detroit Truetrac, 31-Spline Axle, 4.11:1 Ratio, Each

Part Number: MSR-3MAT31BA411

Not Yet Reviewed

Estimated Ship Date: Sep 29, 2025 if ordered today

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Estimated Ship Date: Sep 29, 2025 if ordered today

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