Speedway Motors Ford 9 In Posi Rear End Assembly, 48 Inch Width

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 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 48" (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 48" housing you will need one 24-5/8" long axle and one 22-1/4" long axle. This housing includes (8) T-bolts for the axle bearing retainer plates and (10) studs for the third member.

• 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 43" from flange-to-flange
• Assembled rearend measures 48" from hub-to-hub (axle flange face-to-face)
• 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
• 3rd member sold separately

• Long:
  • 33" length with 9-1/4" of spline
• Short:
  • 29.51" length with 10" of spline

Installation Notes:

Disc brake kits may require increasing the i/d of the center hole in the rotor to match the o/d register or hub pilot on the axle flange, or reducing the diameter of the register or hub pilot on the axle to fit properly to the i/d of the rotor.

When installing new axles in rearends with posi traction differentials, be sure to install the driver's side axle first to keep the splines properly aligned.  Failure to do so may move the two splined gears out of alignment, and it may be difficult to install the driver's side axle properly if the passenger side axle is already installed.

If installation of passenger side axle is done first it may require two people when installing the driver's side axle, with both parties rotating reach axle until splines are in line and the driver's side axle fully sides into the housing.

When cutting axles to desired lengths, it is recommended that the following procedures are performed:

• Normal steel cutting machinery (cold saw, band saw, chop saw, etc.) 
• Using a sleeve around the axle such as a small piece of PVC tubing - this allows:
  • The axle to be spun in place while being cut
  • A perimeter cut around the outer diameter assisting in keeping the cut square
  • Avoiding the build-up of too much heat by doing a straight cut (like a knife though a stick of butter) 

To ensure you get the most out of your new 9 Inch components, it is recommended that you perform a proper break-in process:

• Use a name brand mineral-based gear oil, preferably 85w140 (Extremely high quality synthetic oils may be used once break-in process has been successfully performed)
• Place vehicle on jack stands and let the rearend spin while the vehicle idles - run transmission in both forward and reverse periodically throughout the process
• Continue to run the rearend until the pinion gets hot (place hand on bottom of the differential housing to verify this)
• Proper break-in allows:
  • The ability to install new axles and hit the track the same day without worry
  • Extended life for rearend components
  • Keeps the quality and life of your gear oil

Also available for consideration when a replacement axle bearing retainer for either of the following Ford applications may be required:

• Big Ford Old Style Axle Housing Bearing Retainer Application # 910-48376
• Big Ford New Style Axle Housing Bearing Retainer Application # 910-48379

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

Note: Includes aluminum washers

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

Because there are no friction plates, no friction modifier additive is necessary.  Always use a 80W-90 weight petroleum based gear oil with a GL-5 (or higher) rating, friction additive/modifiers should NOT BE USED.  Synthetic oils and oils containing friction modifiers are not recommended.

Upon receipt and unboxing of your newly purchased 3rd member, prior to installation, it is recommended that the unit be prepped for installation by cleaning the surface of the unit with a form of cleaner such as aerosol brake cleaner and an air hose/compressed air.   This is a normal step in your installation process, and this will properly and sufficiently remove any packaging remnants from the carry case / carry case hardware that may be found to adhered to the 3rd member surface upon receipt.

1310 series U-Joint and Bearing Cap Reatainers Not Included - Sold Seperatly 

1310 Series U-Joint Measurments:

• Yoke Width 3-7/32"
• Cap Diameter  1.062"

Recomended 1310 Universal Joint (U-Joint):

• Speedway 1310 Series Chevy to Chevy U-Joint - Part Number 910-48315
• Dana Spicer 5-153X HD Greasable Cross U-Joint Chevy 1310 Series - Part Number 910-45153
• Heavy Duty Greasable Cross U-Joint, 1310 and Driveshaft U-Bolts - Part Number 910-1606

Recomended U-Joint Bolts/Retainers:

• Universal Drive Shaft U-Bolts, 1-1/16 Inch Cap - Part Number 910-48319
• Fast Shafts BBSK-10 Billet U-Bolt Strap Kit, 1-1/16 Inch - Part Number 910-48200
• Moroso U-Joint Girdle - Part Number 715-8580

These press-in wheel studs from Dorman Products Inc. are engineered to quality standards. The design ensures that your wheels will be tight at all times.

• Corrosion resistant
• Direct replacement for a proper fit
• 1/2"-20 RH thread w/ .685 Knurl
• 1.9" long
• Serrated Stud
• Box of 10
• Steel Construction

Applications:  These wheel studs will work on a variety of race/street vehicles but are designed as direct replacements for:

• 2007-11 Dodge Nitro
• 2002/2008-12 Jeep Liberty
• 2003-06 Jeep Wrangler (Trulok Differential)

Instructions (PDF)