Speedmaster Differential Housing Stud

The studs that clamp a third member into its housing rarely get attention, but they carry a heavy load. Every time the driveline loads up, the stud fasteners keep the differential carrier seated square against the housing. If they stretch or loosen, gear mesh and bearing alignment suffer. Speedmaster's differential housing stud offering is small and focused, and it is built around one of the most popular rear-end platforms in performance and racing: the Ford 9-inch.

Ford 9-Inch Housing-to-Third-Member Stud Kit

Speedmaster's listing in this category is a Ford 9" housing-to-third-member stud kit with 3/8" UNC threads. It is made for the 9-inch builder who wants fresh, matched hardware when installing a third member, rather than reusing worn studs or sorting through mixed fasteners. A complete kit simplifies assembly and helps ensure every position gets the same grade and thread specification.

The Ford 9-inch is common in drag racing, circle track, street/strip cars, and restomods, so this hardware has a wide audience. Studs also suit builds where the third member is pulled regularly for gear changes, because they hold the carrier in position while you install the nuts.

Part of a Complete Rear-End Ecosystem

What sets Speedmaster apart in this niche is the range of parts it makes around the stud. The company designs and manufactures complete driveline components, including modular differential housings, axle tubes, differential covers, carriers, pinion supports, spools, ring and pinion gears, and fully assembled third members. Its Ford 9-inch modular housings, for example, are offered as housing sections and as tube combos that include hardware, so the stud kit fits naturally into a larger build plan.

Speedmaster's third member assemblies are built by its in-house differential technicians, who draw on decades of motorsport experience from V8 Supercars to Group 1 drag racing. That background shapes how its fastener products are specified: they are meant to work inside rear ends that see real track abuse.

What to Check Before You Buy

• Thread size and length: Confirm the 3/8" UNC specification matches your housing and third member setup.
• Application: This kit is intended for Ford 9-inch housings. Other differential bearing cap and carrier stud kits are separate parts.
• Fresh hardware: Replace studs and nuts when you rebuild, especially after hard launches or tight-tolerance gear setups.
• Torque and lubricant: Follow the torque specification for your fasteners, and use thread sealant where the stud passes into a wet area.

Company Background

Speedmaster began in 1979 as Pete's Performance, a small speed workshop building engines for local racers, and grew into a manufacturer with operations on three continents. It holds multiple patents and has earned SEMA Global Media Awards, and its SFI-certified products and motorsport sponsorships reflect a racing-first culture that carries through to its driveline parts.

To see the full range of products from this manufacturer, visit the Speedmaster brand page. For a broader look at fasteners that secure differential housings, including options from other manufacturers, browse the Differential Housing Stud category.