Product Summary

Universal Fit, Rear Position, Semi-Floating Axle Type

  • Housing measures 53" from flange-to-flange, Assembled rearend measures 58" from hub-to-hub (axle flange face-to-face)
  • 3" O.D. axle tubes with 3/16" wall thickness are internally reinforced for additional strength, less flex
  • Clutch style positraction differential gives limited slip performance and quiet operation (no gears clicking!)
  • Third member is precision assembly for the correct backlash, preload, and proper amount of pinion shims to ensure the correct pattern on the ring gear teeth
  • Axle flanges are dual-drilled for both 5 on 4-1/2" Ford/Mopar and 5 on 4-3/4" GM wheel bolt patterns

Comes as a Kit

Key Specs

MFG. Part #91606187
BrandSpeedway Motors
Axle TypeSemi-Floating

Need To Know

Quick and Easy Returns

Return Policy


Speedway Fabricated Ford 9 Inch Rearend Axle 58 Inch Housing

Looking for a budget-friendly, rock-solid foundation for your custom rear suspension? Look no further. Our fabricated steel Ford 9 inch axle housings feature all-new, USA-made components for maximum durability. It's an evolution of the rugged and reliable 9 inch Ford platform.

Designed with the Builder in Mind

This housing is pumpkin-centered with uniform-length axle tubes, side-to-side. So mounting suspension brackets, especially on triangulated 3-link and 4-link systems, is much easier. Unlike factory stamped housings, these fabricated plate-steel center sections provide a wide, flat surface for easy bracket attachment. Note that the pumpkin-centered design will offset the pinion yoke about 1" to the passenger side.

Axle tubes are 3"O.D. with a 3/16"wall thickness. Heavy-wall tubes, along with a larger center section, significantly reduce distortion during welding of rear-link brackets or spring pads. Billet steel "New Big Ford"(Torino) style bearing ends are fixture-welded (3.150"O.D. bearing, with 2.50"axle flange offset).

Improved Design for Greater Durability

In addition to the heavy-duty bearing ends, the axle tubes are supported with bracing inside the large center housing. This reduces flex in the rear end housing, which is something you won't find on stamped factory 9 inch housings. Plus, gears stay well-lubed and run cooler thanks to a large-capacity fabricated center (holds more gear oil than stamped housings). Axle is vented on the driver's side.

Yet, with improved durability, our fabricated axle housing is on average 2 pounds lighter than stock style housings of the same size! Add your choice of axle shafts and third member (sold separately), and you are ready to roll. Equip your race car, hot rod or 4X4 with Ford 9 inch parts from Speedway Motors to ensure there are no weak links in your driveline combination.

Total wheel-to-wheel mounting surface width is 58" (from hub-to-hub). The pumpkin is centered in the housing, which puts the pinion 1" offset from center, requiring different length axle shafts. For this 58" housing the kit includes one 27-3/8" long axle and one 29-5/8" long axle. This housing includes (8) T-bolts for the axle bearing retainer plates and (10) studs for the third member.

  • Made in the USA fabricated steel center section
  • 3" O.D. axle tubes with 3/16" wall thickness
  • Axle tubes are internally reinforced for additional strength, less flex
  • Billet steel "New Big Ford" (Torino) style bearing ends
  • Accepts brake kits for 2.50" axle shaft flange offset (from housing flange)
  • Housing measures 53" from flange-to-flange
  • Assembled rearend measures 58" from hub-to-hub (axle flange face-to-face)
  • Improved design weighs only40.2 lbs vs 42.5 lbs stock-style fabricated housings
  • Centered pumpkin w/ 1" offset pinion yoke for easy suspension mock-up
  • Greater-than-stock capacity center section holds more gear oil and runs cooler
  • Requires different length axle shafts, left/right
  • Includes vent on driver side axle tube
  • Includes studs for 3rd member and 3/8"T-bolts for bearing retainer plates

Speedway Motors Ford 9 Inch Clutch-Style Posi Differential Third Members

As featured on Classic Truck's Week to Wicked. Watch the transformationhere!

Assembled by Professionals

Hand-assembled by trained experts in-house, our Ford 9-inch third members are built from quality components with an exact step-by-step process. We bring this combination of precision assembly and quality components to you at a price that can't be beat. We trust these third members so much, they're the go-to choice for our own rides, from the street to the track.

Tough, Nodular Iron Center Section

Our Ford 9 Inch Nodular Iron Third Member Center Section Carrier starts with a NEW casting with over 4 lbs. of additional material in critical areas. Nodular (ductile) iron is much more resistant to fracturing than OEM "gray"iron. Extra ribbing reinforces the case and rearmost pinion support (pilot bearing).

Thick, forged steel bearing caps surround the carrier bearings, all securely held in place with precision Grade 8 cap screws. The improvements continue with rugged billet steel adjuster nuts and heavy-duty keepers to ensure your ring gear settings are maintained. All mounting surfaces are precision machined to ensure a consistent, flat surface for a positive gasket seal (no more leaks on your shop floor). An oil fill plug is included.

Precision Assembled for Proper Ring Gear Teeth Pattern

Getting a proper pattern on the ring gear teeth is crucial. Our time-proven, step-by-step process ensures the correct backlash, preload, and proper amount of pinion shims to ensure the correct pattern on the ring gear teeth. Our gears use use cold-rolled 8620 steel, known for its long-wear and durability.

To ensure a proper gear pattern, we use a stronger "Daytona"style pinion bearing support to maintain that critical pinion depth setting. Stronger due to its larger bearings, our Daytona pinion support also uses the spacer-and-shim setup to maintain critical pinion depth settings under high load, unlike traditional crush sleeves which often compress further, take out your preload and lead to failure. With solid bearing spacers and the proper shims, we eliminate this problem and make setting preload easy and repeatable during installation, service and gear changes. Since preload is already set, simply torque the pinion nut to 160 ft./lbs. and you're good to go. The pinion gear is connected to our new, forged steel "Ford short”, 1310-type pinion yoke.

Clutch-Style Posi Differential with Proven Performance

Our clutch-style posi differential gives you maximum traction. Based on the original limited-slip designs of the OEMs, these differential units provide the added benefits of experience over millions of miles and decades of proven reliability. A clutch-style operation means no clicking around corners and our posis feature heat-treated spider gears in a forged steel case. We've taken this posi to the next step in performance with increased clutch pressure and holding power, suiting it well for heavy-duty street car applications.

This differentialhas performed well in our Week to Wicked 1952 Chevy Truck, handling the job of transferring a 430 HP GM Performance LS3 to the ground.

  • Clutch style, spider gear differential = proven reliability
  • Spring-loaded clutch pack with improved grip over OEM designs
  • Ideal for street tires and medium horsepower applications
  • Housed in a Fully Machined, Reinforced Forged Steel Case

Proven Reliability

We run what we sell. Our third member units are the go-to choice for our own rides and we have built these units to last with high quality hardware and components. Tapered steel roller bearings minimize friction, better handle thrust loads and increase load carrying capacity. The ring gears are assembled with Grade 9 bolts with a tensile strength of 180,000 psi, a 15% increase over Grade 8 hardware. Heavy duty Grade 8 carrier cap bolts, a lock-style pinion nut with pre-applied Loctite and high-quality grade 5 pinion support bolts make our third member near-bulletproof.

Units include a Viton® pinion seal providing long lasting oil and chemical resistance. This seal retains elasticity up to 399°F (204°C) and intermittently up to 600°F (316°C) This high temp seal helps eliminate pinion leaks, reduces maintenance and keeps the third member properly lubricated. A carrier-to-housing gasket is available separately.

Our hand-assembled Ford 9 inch third member assemblies are made-to-order. We keep a supply of the most popular gears in stock, with most units built within 2-3 days. Our third-member units are shipped in a durable, reusable poly storage case, perfect for keeping multiple gear sets stored and ready for the track.


  • Hand-assembled by our trained technicians for an unbeatable combination of quality and value
  • Track-tested durability in our own cars – we race what we sell
  • Precision assembly for the correct backlash, preload, and proper amount of pinion shims to ensure the correct pattern on the ring gear teeth
  • Ring and pinion gears of 8620 cold-rolled steel for long wear
  • Nodular iron housing is stronger than OEM "gray"iron and has 4 lbs of additional reinforcement
  • Large bearing "Daytona"style pinion bearing supports for strength and reliability
  • Spacer and shim setup maintains critical pinion depth settings and easier to service than traditional crush sleeves
  • Clutch style positraction differential gives limited slip performance and quiet operation (no gears clicking!)
  • Ring gears assembled with Grade 9 hardware, 15% stronger in tensile strength than Grade 8
  • Viton® pinion seal, resistant to chemicals and high temperatures
  • Grade 8 Carrier cap bolts
  • Lock-style pinion nut with pre-applied Loctite®
  • Grade 5 pinion support bolts
  • Includes form fitted, reusable red poly storage case

Currie 9 Inch Ford 31 Spline Axle Shafts

This custom cut and splined Currie Enterprises axle shaft is for Speedway housing91046254or 91047256 and other 9" Ford rearends. Works with New Big Ford (Torino) bearing ends. Flanges are dual-drilled for both 5 on 4-1/2" Ford/Mopar and 5 on 4-3/4" GM wheel bolt patterns.

  • Induction heat treated 1541 forged alloy
  • 31-spline
  • (1) 27.375" long
  • (1) 29.625" long
  • Fits 91046254 pumpkin centered housing
  • Fits 91047256 pinion centered housing
  • Works with New Big Ford (Torino) bearing ends
  • 2.5" brake space offset
  • 2.8" register hub
  • Dual-drilled wheel bolt pattern

Includes axle shaft, axle bearing, axle seal, bearing retainer, and two sizes of wheel studs (1/2"-20 Ford/Moparand 7/16"-20 GM).

Speedway 9 Inch Ford Rearend Axle Housing 3rd Member Pumpkin Gasket

Our reusable rear differential gaskets have a steel core and non-stick coating. Fits 9" Ford rear axle third member housings.

Speedway Third Member Mounting Hardware

Used to attach the 3rd member (pumpkin) to the rearend housing, works with Ford 8" and 9" rear axles.

Note:Includes aluminum washers



MFG. Part #91606187
BrandSpeedway Motors
Axle TypeSemi-Floating
Overall Width58"
Differential IncludedYes
Differential TypeLimited Slip
Ring Gear Size9 Inch
Spool WeightStandard
Axle Splines31
Tube O.D.3"
Housing MaterialSteel
Bolt PatternDual: 5 on 4.5" | 4.75"
Wheel Studs IncludedYes
Yoke U-Joint Series1310
Yoke Width3-7/32"
Hardware IncludedYes
Sold in QuantityKit
Brakes IncludedNo
Bearings IncludedYes
Seals IncludedYes
Rotors IncludedNo