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.
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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: Today
Estimated Ship Date: Today
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: Today
Estimated Ship Date: Today
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: Today
Estimated Ship Date: Today
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: Today
Estimated Ship Date: Today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Detroit Truetrac, 3.50:1 Ratio, Daytona Pinion Support,1350 Series Yoke,Each
Part Number: MSR-3MST31AN350
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 35-Spline, Nodular Iron Case, Wavetrac, 3.50:1 Ratio, Daytona Pinion Support,1350 Series Yoke, Each
Part Number: MSR-3MNW35AA350
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Aluminum Case, Detroit Truetrac, 3.50:1 Ratio, Daytona Pinion Support, 1350 Series Yoke,Each
Part Number: MSR-3MAT31AA350
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Aluminum Case, Detroit Truetrac, 3.25:1 Ratio, Daytona Pinion Support, 1350 Series Yoke,Each
Part Number: MSR-3MAT31AA325
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 33-Spline, Nodular Iron Case, Spool, 4.29:1 Ratio, 10-Hole Pro Pinion Support, 1350 Series Yoke, Each
Part Number: MSR-3MNS33AP429P
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Detroit Truetrac, 3.50:1 Ratio, Daytona Pinion Support,1350 Series Yoke,Each
Part Number: MSR-3MNT31AN350
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 35-Spline, Nodular Iron Case, Detroit Truetrac, 4.11:1 Ratio, Daytona Pinion Support,1350 Series Yoke,Each
Part Number: MSR-3MNT35AA411
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 28-Spline, Nodular Iron Case, Trak-Lok, 3.70:1 Ratio, Daytona Pinion Support, 1350 Series Yoke,Each
Part Number: MSR-3MNC28AA370
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 28-Spline, Nodular Iron Case, Trak-Lok, 3.50:1 Ratio, Daytona Pinion Support,1350 Series Yoke, Each
Part Number: MSR-3MSC28AN350
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 35-Spline, Nodular Iron Case, Spool, 3.89:1 Ratio, Daytona Pinion Support, 1350 Series Yoke, Each
Part Number: MSR-3MNS35AA389
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Yukon Trak-Lok, 3.70:1 Ratio, Daytona Pinion Support, 1350 Series Yoke,Each
Part Number: MSR-3MNC31AN370
Not Yet Reviewed
Estimated Ship Date: Today
Estimated Ship Date: Today
Third Member Complete Assembly, ZR12, TrueTrac, 3.73:1 Gear Ratio, 33-Spline, Aluminum Case, 1350 Yoke, Each
Part Number: DSR-070650373DS
Not Yet Reviewed
Estimated Ship Date: Today
Estimated Ship Date: Today
FN988 STD CASE 31 SPL TT 4.10 RATIO 1350, With REM Finishing
Part Number: DSR-070880410DSR
Not Yet Reviewed
Estimated Ship Date: Nov 24, 2026 if ordered today
Estimated Ship Date: Nov 24, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Trak-Lok, 3.25:1 Ratio, Daytona Pinion Support,1350 Series Yoke, Each
Part Number: MSR-3MSC31AN325
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
FORD 9'' 3.50 N GEAR 31 SPLINE TRUETRAC
Part Number: DSR-90-20015
Not Yet Reviewed
Estimated Ship Date: Nov 24, 2026 if ordered today
Estimated Ship Date: Nov 24, 2026 if ordered today
FN988 TA CASE 31 SPL TT 3.31 RATIO 1350
Part Number: DSR-070881-331DS
Not Yet Reviewed
Estimated Ship Date: Today
Estimated Ship Date: Today
Third Member Complete Assembly, Ford 9 in., 35-Spline, Aluminum Case, Spool, 4.11:1 Ratio, 10-Hole Pro Pinion Support, 1350 Series Yoke,Each
Part Number: MSR-3MAS35AT411P
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Aluminum Case, Detroit Truetrac, 3.70:1 Ratio, Daytona Pinion Support, 1350 Series Yoke,Each
Part Number: MSR-3MAT31AA370
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Detroit Truetrac, 3.00:1 Ratio, Daytona Pinion Support,1350 Series Yoke,Each
Part Number: MSR-3MNT31AN300
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Detroit Truetrac, 3.89:1 Ratio, Daytona Pinion Support,1310 Series Yoke,Each
Part Number: MSR-3MNT31BN389
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
Third Member Complete Assembly, Ford 9 in., 31-Spline, Nodular Iron Case, Detroit Truetrac, 4.57:1 Ratio, Daytona Pinion Support,1350 Series Yoke,Each
Part Number: MSR-3MST31AN457
Not Yet Reviewed
Estimated Ship Date: Dec 21, 2026 if ordered today
Estimated Ship Date: Dec 21, 2026 if ordered today
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