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 114

Moser Engineering Ford 9 in. Third Member Assemblies 3MNS35BN325

Third Member Complete Assembly, Ford 9 in., 35-Spline, Nodular Iron Case, Steel Main Cap, Bolt Retention, 3.25:1 Ratio, 1310 Series Yoke, Each

Part Number: MSR-3MNS35BN325

Not Yet Reviewed

Estimated Ship Date: Aug 25, 2025 if ordered today

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Estimated Ship Date: Aug 25, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MAS35BA411

Third Member Complete Assembly, Ford 9 in., 35-Spline, Aluminum Case, Aluminum Main Cap, Bolt Retention, 4.11:1 Ratio, 1310 Series Yoke, Each

Part Number: MSR-3MAS35BA411

Not Yet Reviewed

Estimated Ship Date: Aug 25, 2025 if ordered today

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Estimated Ship Date: Aug 25, 2025 if ordered today

Moser Engineering Ford 9 in. Third Member Assemblies 3MAS31BA514

Third Member Complete Assembly, Ford 9 in., 31-Spline, Aluminum Case, Aluminum Main Cap, Bolt Retention, 5.14:1 Ratio, 1310 Series Yoke, Each

Part Number: MSR-3MAS31BA514

Not Yet Reviewed

Estimated Ship Date: Aug 25, 2025 if ordered today

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Estimated Ship Date: Aug 25, 2025 if ordered today

Moser Engineering Chrysler 8.75 in. Third Member Assemblies 875NA30B373

Third Member Complete Assembly, Chrysler 8.75 in., 30-Spline, Nodular Iron Case, Steel Main Cap, Bolt Retention, 3.73:1 Ratio, 1310 Series Yoke, Each

Part Number: MSR-875NA30B373

Not Yet Reviewed

Estimated Ship Date: Sep 3, 2025 if ordered today

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Estimated Ship Date: Sep 3, 2025 if ordered today

PEM Racing Third Member Complete Assembly CSMS51428