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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: Tomorrow
Estimated Ship Date: Tomorrow
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, 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: Tomorrow
Estimated Ship Date: Tomorrow
FORD 9'' 3.50 N GEAR 31 SPLINE TRUETRAC
Part Number: DSR-90-20015
Not Yet Reviewed
Estimated Ship Date: May 4, 2026 if ordered today
Estimated Ship Date: May 4, 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: Tomorrow
Estimated Ship Date: Tomorrow
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: May 4, 2026 if ordered today
Estimated Ship Date: May 4, 2026 if ordered today
DROP OUT ASSEMBLY
Part Number: YGA-13270
Not Yet Reviewed
Estimated Ship Date: May 18, 2026 if ordered today
Estimated Ship Date: May 18, 2026 if ordered today
DROPOUT ASSEMBLY
Part Number: YGA-13210
Not Yet Reviewed
Estimated Ship Date: May 12, 2026 if ordered today
Estimated Ship Date: May 12, 2026 if ordered today
9-Inch Third Member Complete Assembly, 4.56 Gear Ratio Spool. 35 Spline, Nodular Iron Case, 1350 Yoke, Each
Part Number: CUR-CE-9SP456R50
Not Yet Reviewed
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
Center Section
Part Number: AEV-11060200AG
Not Yet Reviewed
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
5.29, V6, ARB, Polished
Part Number: TGI-301471-1-KIT
Not Yet Reviewed
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
4.88 V6 Spool 29-Spline
Part Number: TGI-304098-1-KIT
Not Yet Reviewed
Estimated Ship Date: Tomorrow
Estimated Ship Date: Tomorrow
Dropout Assembly for Ford 9in Diff w/Trac-Lok LSD, 31 Spline, 3.25 Ratio
Part Number: YGA-13205
Not Yet Reviewed
Estimated Ship Date: May 12, 2026 if ordered today
Estimated Ship Date: May 12, 2026 if ordered today
DROPOUT ASSEMBLY
Part Number: YGA-13209
Not Yet Reviewed
Estimated Ship Date: May 12, 2026 if ordered today
Estimated Ship Date: May 12, 2026 if ordered today
Yukon Dropout Assembly
Part Number: YGA-13229
Not Yet Reviewed
Estimated Ship Date: May 12, 2026 if ordered today
Estimated Ship Date: May 12, 2026 if ordered today
YUKON DROPOUT ASSEMBLY
Part Number: YGA-13261
Not Yet Reviewed
Estimated Ship Date: May 15, 2026 if ordered today
Estimated Ship Date: May 15, 2026 if ordered today
4.88 V6 Detroit
Part Number: TGI-140036-1-KIT
Not Yet Reviewed
Estimated Ship Date: May 18, 2026 if ordered today
Estimated Ship Date: May 18, 2026 if ordered today
5.29 HiP Detroit
Part Number: TGI-140039-1-KIT
Not Yet Reviewed
Estimated Ship Date: May 18, 2026 if ordered today
Estimated Ship Date: May 18, 2026 if ordered today
5.29 V6 Spool
Part Number: TGI-140069-1-KIT
Not Yet Reviewed
Estimated Ship Date: May 18, 2026 if ordered today
Estimated Ship Date: May 18, 2026 if ordered today
Third Member Complete Assembly, Assembled 29-Spline Super Finish 3rd Members For Toyota 8" Axles- 4cyl 4.88 Spool
Part Number: TGI-304618-1-KIT
Not Yet Reviewed
Estimated Ship Date: May 18, 2026 if ordered today
Estimated Ship Date: May 18, 2026 if ordered today
FORD 9'' 3.70 N GEAR 31 SPLINE TRUETRAC
Part Number: DSR-90-20020
Not Yet Reviewed
Estimated Ship Date: May 4, 2026 if ordered today
Estimated Ship Date: May 4, 2026 if ordered today
FORD 9'' 4.11 N GEAR 31 SPLINE TRUETRAC
Part Number: DSR-90-20030
Not Yet Reviewed
Estimated Ship Date: May 4, 2026 if ordered today
Estimated Ship Date: May 4, 2026 if ordered today
FORD 9'' 3.89 N GEAR 31 SPLINE TRUETRAC
Part Number: DSR-90-20025
Not Yet Reviewed
Estimated Ship Date: May 4, 2026 if ordered today
Estimated Ship Date: May 4, 2026 if ordered today
