Product Summary
Rear Position, Axle Shafts Included, 31 Axle Splines
- Designed to replace the original 1968-1972 GM A-Body rearend housing
- Compatible with the stock 4-link trailing arm rear suspension found in your Chevelle, Malibu, El Camino, Sprint, GTO, LeMans, Tempest, F85, Cutlass, 442, Special, Skylark and Gran Sport
- Third member is hand-assembled by our trained technicians for an unbeatable combination of quality and value
- Precision assembly for the correct backlash, preload, and proper amount of pinion shims to ensure the correct pattern on the ring gear teeth
- Includes a reusable differential gasket with a steel core, mounting hardware, 4oz bottles of Redline friction modifier and forged u-bolts.
Housing and Axles
These bolt-in rear axle packages are designed to replace the original ’68-’72 GM A-Body rearend housing and are compatible with the stock 4-link trailing arm rear suspension found in your Chevelle/Malibu/El Camino/Sprint/GTO/LeMans/Tempest/F85/Cutlass/442/Special/Skylark/Gran Sport. The major advantages gained by upgrading to a Ford 9″ axle include:
- Greatly increased strength (reliability)
- The variability of the housing to accept almost any gear ratio from 2.47:1 to 6.14:1
- A drop-out third member for ease of service
- Steel axle retainers which keep the axle/wheel in place in the event of axle failure
If you’re upgrading your rear end and axles though, why stop there? This kit also includes everything you need to convert your stock rear suspension to a coil-over suspension with a QA1 Coil-Over Conversion Kit. QA1’s kit includes specifically designed mounting brackets and single adjustable aluminum shocks for the 1968-72 A-Body with all hardware included. To round it all out we have also thrown in a new sway bar, new trailing arms (with hardware), and new trailing arm mount braces. Give the rear of your car the upgrades it deserves! Just add the third member and brake kit of your choice (both sold separately) to complete your installation.
Kit includes:
- 990-06872 Speedway Ford 9 Inch Bolt-In Rear End Axle for 1968-72 GM A-Body
- 721-52340 QA1 RCK52340 Rear Coil-Over Conversion Kit, 1964-72 A-Body, 150 Pound
- 916-6472.1 64-72 A-Body Trailing Arm Hardware
- 916-6472.2 64-72 1.125 Inch Rear Swaybar
- 916-6472.L 64-72 A-Body Heavy Rear Lower Trailing Arm, Left Side
- 916-6472.R 64-72 A-Body Heavy Rear Lower Trailing Arm, Right Side
- 916-6872 Trailing Arm Mount Brace, 1968-72 A-Body, Pair
- (2) 916-1968.1 68-72 A-Body Adjustable Upper Arm
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 differential has 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.
Features
- 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
Carrier Studs
Housing studs and ring gear bolts complete the package for your racing or street use 9″ Ford axle.
Side bell thru bolts torque to 40-45 lbs.
Knurl diameter .398-.403 ”
Install Kit
Make the installation of your new Posi-Traction Third Member a breeze! We’ve packed together some of the most commonly needed items to ease your installation with one click!
Kit Includes:
- 919-0916 Speedway 3rd Member Mounting Hardware for 8/9 Inch Rearends
- Used to attach the 3rd member (pumpkin) to the rearend housing
- Works with Ford 8″ and 9″ rear axles
- Includes aluminum washers
- 919-2300 Speedway 9 Inch Ford Rearend Axle Housing 3rd Member Pumpkin Gasket
- Reusable Differential Gasket
- Steel Core
- Non-Stick Coating
- 910-48319 Universal Drive Shaft U-Bolts, 1-1/16 Inch Cap
- Speedway universal drive shaft U-bolts are forged steel for 50% more strength than standard units
- Fits U-joints with 1-1/16″ diameter caps
- U-bolt set for #80292417 – Speedway Ford 9 Inch Rearend 1310-Series Small Pinion Yoke
- From end of threads to inside of radius at deepest point is 1.708″ or 1-11/16″ plus
- Center to center of threaded ends is 1-3/8″
- 795-9751 Valvoline VV975 Synpower 75W90 Gear Oil, 3 Quarts
- Thermally stable, extreme-pressure gear lubricant
- Designed to operate in both high and low extreme-temperature conditions
- Recommended for limited-slip hypoid differentials and is compatible with conventional gear lubricants
- Maintains excellent low-temperature fluid protection
- Provides outstanding thermal stability for cleanliness and longer service life
- Contains special additives to assist in protecting gear teeth from rust and corrosion
- Contains special additives to reduce chattering in limited-slip differentials
- 3 quarts
- 60780301 Red Line 80301 Limited-Slip Friction ModifierAdditive, 4 oz.
- Compatible with both petroleum and synthetic gear oils
- Reduces break-in temps as much as 50°F
- Add 1oz at a time to clutch-type limited slip or posi-traction units to eliminate chatter
- Exceeds API GL-5 specifications
- Engineered to provide the highest degree of protection and efficiency for better mileage, longer drain intervals, and less wear
- 4 ounce bottle
- Recommended Dosage:
- Use 4% for prevention of limited slip chatter in broken-in units (typical one 4 oz. bottle) or 4 to 8% for the break-in of new differentials.
- In non-limited-slip racing differentials and quick-change units using the Red Line ShockProof Gear Oils an additional 3 to 6% Red Line Limited-Slip Differential Friction-Modifier / Break-In Additive is recommended.
Kit Includes
- (1) 1968-72 A-Body Ford 9 Inch Housing/Axles with Coilover Suspension
- (1) Ford 9 Inch Posi Differential 3rd Member, 31 Spl, 3.50 Gear Ratio
- (1) 9 Inch Ford Rearend Axle Housing 3rd Member Carrier Studs
- (1) Speedway Ford 9 Inch Posi Traction Third Member Install Kit.
Guides & Documents
-
Axle Assemblies Instruction Sheet (9100280)(PDF)
-
Coilovers Instruction Sheet (72152340)(PDF)
-
Differential Third Members Instruction Sheet (91049345)(PDF)
-
Differential Oil Additives Guide/Document (60780301)(PDF)
-
Differential Fluid Guide/Document (7958897851)(PDF)
KEY SPECS |
|
---|---|
MFG. Part # |
9100280 |
Brand |
Speedway Motors |
Position |
Rear |
Axle Splines |
31 |
Axle Type |
Semi-Floating |
Brakes Included |
No |
Wheel Studs Included |
Yes |
Wheel Bolt Pattern (in.) |
5×4.75 in. |
Material Type |
Nodular Iron |
Finish |
Natural |
Gear Ratio |
3.50:1 |
Differential Type |
Limited Slip |
Tube O.D. |
3″ |
Housing Material |
Steel |
Bolt Pattern |
5 on 4.75″ |
Yoke U-Joint Series |
1310 |
Hardware Included |
Yes |
Rotors Included |
No |
GENERAL |
|
Axle Shafts Included |
Yes |
Third Member Included |
Yes |
Ring and Pinion Included |
Yes |
Bearings Included |
Yes |
Seals Included |
Yes |
Differential Included |
Yes |
Sold in Quantity |
Kit |