91049346-31-370 SPEEDWAY MOTORS Posi Member Spl Ford

Review SPEEDWAY MOTORS Fits Ford Inch Posi Aluminum Case 3rd Member 31 Spl 3.70 Ratio for FORD

Introducing the Speedway 91049346-31-370 Ford Posi 3rd Member 31 Spl 3.70, a high-performance component designed to enhance the power delivery and durability of your Ford differentials. This 3rd member assembly is engineered specifically for Ford vehicles requiring a 3.70 gear ratio and a 31-spline output shaft.

Constructed from premium materials, this 3rd member is built to last. The housing is made of heavy-duty cast iron, ensuring robustness and resistance to the extreme loads and stresses placed upon it. The spline design of the output shaft is precisely machined to provide a secure and reliable connection to the differential gears.

The Speedway 91049346-31-370 is also engineered to accommodate Ford's Posi-Traction limited-slip differential. This advanced differential system improves traction and stability by distributing power evenly between the wheels, providing better grip and control, especially during cornering and acceleration.

This 3rd member assembly is an excellent choice for Ford enthusiasts looking to upgrade their differentials for superior performance and durability. It is a direct replacement for the OEM part, ensuring a seamless installation process. The Speedway 91049346-31-370 Ford Posi 3rd Member 31 Spl 3.70 is backed by a comprehensive warranty, providing peace of mind and protection against manufacturing defects.

In summary, the Speedway 91049346-31-370 Ford Posi 3rd Member 31 Spl 3.70 is a top-quality, performance-enhancing component designed for Ford vehicles requiring a 3.70 gear ratio and a 31-spline output shaft. It is built from premium materials, engineered for compatibility with Ford's Posi-Traction limited-slip differential, and backed by a comprehensive warranty. Upgrade your Ford differential with this robust and reliable 3rd member assembly.

Pros and Cons of Buying Speedway 91049346-31-370 Ford POSI 3rd Member 3.1 Spl 3.70

a. Compatibility: This 3rd member is specifically designed for Ford applications, ensuring a perfect fit and seamless integration with other drivetrain components.

b. Durability: The Speedway 91049346-31-370 is known for its robust construction, capable of handling high horsepower applications and heavy-duty usage.

c. Cost-Effective: Compared to OEM alternatives, aftermarket 3rd members, like the Speedway 91049346-31-370, often offer more affordable pricing.

d. Improved Performance: A stronger 3rd member can lead to improved vehicle performance, including increased torque capacity and better power transfer.

a. Installation Complexity: Installing a 3rd member can be a challenging process, requiring specialized tools and a good understanding of drivetrain systems.

b. Potential Warranty Issues: Since this is an aftermarket part, there may be limited or no warranty coverage compared to OEM components.

c. Quality Variability: While many aftermarket parts are of high quality, there can be variability in manufacturing processes and materials, which may impact the longevity and reliability of the part.

The Speedway 91049346-31-370 Ford POSI 3rd Member 3.1 Spl 3.70 offers several advantages, including compatibility, durability, cost-effectiveness, and potential performance improvements. However, it also comes with some disadvantages, such as installation complexity, potential warranty issues, and quality variability.

If you're looking to upgrade your Ford's drivetrain system with a stronger, more durable 3rd member, the Speedway 91049346-31-370 could be an excellent choice. However, it's crucial to understand the installation process, ensure you're purchasing from a reputable supplier, and consider the potential impact on your vehicle's warranty. Considering these factors and weighing the pros and cons, if you're confident in your abilities and willing to accept the risks, then this aftermarket 3rd member could provide significant benefits to your Ford.

Details:

Units include a Vito pinion seal providing long-lasting oil and chemical resistance. Lightweight aluminum housing has forged caps and extra beef where needed while saving 12 lbs. Our third-member units are shipped ready to install in a durable, reusable poly storage case. Billet steel adjuster nuts with heavy duty keepers to maintain ring pinion settings.

Includes form-fitted, reusable red poly storage case. They are among the heaviest car-based axle assemblies known. Stronger due to its larger bearings, our Dayton pinion support also uses a fixed spacer-and-shim setup maintain critical depth settings under high load, unlike traditional crush sleeves which often compress further affecting the reload setting and leading failure. Based on the original limited-slip designs of ems, these differential units provide added benefits experience over millions miles and decades proven reliability.

Part # 91049346-31-370 condition new brand Speedway motors sold each details a356-t6 housing with 3.062-inch carrier bearing race diameter. Precision assembly for the correct backlash, reload, and pinion shims to ensure gear pattern. A gear-style operation means no ing around corners like lockers have and our posi units feature heat-treated spider gears in a forged steel case. Hand-assembled by our trained technicians for an unbeatable combination of quality and value, precision assembly the correct backlash, reload, proper amount pinion shims to ensure pattern on ring gear teeth, our ready install aluminum 9-inch third member is ideal street tires medium horsepower applications, lightweight housing has forged caps extra beef where its needed while saving approximately 12 lbs.

Standard gear oil fill location on drivers side of casting. Headquarters. While they are known for their strength, also weight. Ring and pinion gears made from 8620 cold-rolled steel for long wear.

We bring this combination of precision assembly and quality components to you at a price that can't be beat. Tapered steel roller bearings minimize friction, better handle thrust loads and increase load-carrying capacity. For your car or truck that means quicker acceleration, better handling, and even improved braking, as suspension axle can respond more quickly to changing road conditions, keeping the tires in contact with.

Proper ring pinion gear teeth mesh pattern for quiet operation: getting a proper pattern on the ring gear teeth is crucial. Yes, I recommend this product. Over cast iron versions, gear posi-traction differential gives limited slip performance and quiet operation no ing/ratcheting gears like a locker has. Our time-proven, step-by-step process ensures the correct backlash, reload, and proper amount of pinion shims to ensure pattern on ring gear teeth for maximum performance minimum noise.

Lock-style pinion nut with pre-applied lactate. With solid bearing spacers and the proper shims, we eliminate this problem make setting reload easy repeatable during installation, service, gear changes. Spacer and shim setup maintains critical pinion depth settings is easier to service than traditional crush sleeves. Vito pinion seal, resistant to chemicals and high temperatures.

specifications differentialsdepo:

• for makes: Ford
• brand: Speedway Motors
• type: Differential Third Members
• item length: 18.00
• item width: 13.000
• california prop 65 warning: True
• ean: 9104934631370

shipping differentialsdepo:

• class: standard
• transit: 3-8 days
• carrier: ups
• service: ups ground
• type: fixed

offer differentialsdepo:

• options: ship-to-home
• in stock #: 5
• availability: in stock
• sold #: 15
• started: april 22, 2026
• prices: $8.70–$84.99
• item condition:
  • New
  • Used
  • New other (see details)

general differentialsdepo:

• category: Auto Parts > Transmission Drivetrain > Differentials > Assemblies

seller differentialsdepo:

• city: lincoln, nebraska
• # reviews: 360865
• rating: 99.8%

returns differentialsdepo:

• time: 30 days
• policy: returns accepted
• paid by: seller

payments differentialsdepo:

• other
• wallet: paypal
• credit card: discover