Are all Ford 9-inch rear ends the same?
The Ford 9-inch rear end is one of the most iconic and widely used rear differentials in automotive history. Known for its strength, versatility, and ease of customization, it has been a favorite among hot rodders, drag racers, and off-road enthusiasts for decades. However, not all Ford 9-inch rear ends are created equal. In this article, we’ll explore the differences and what you need to know when working with or purchasing one.
What Makes the Ford 9-Inch Rear End Unique?
The Ford 9-inch rear end earned its reputation for being durable and easy to work on. Its removable third member (also known as the "pumpkin") allows for quick gear ratio changes, and its design can handle significant amounts of torque. These features make it a popular choice for high-performance applications.
Are All Ford 9-Inch Rear Ends the Same?
No, not all Ford 9-inch rear ends are the same. While they share a common design, there are several variations that can affect their performance and compatibility. Here are the key differences to consider:
- Housing Design: Ford produced different housing designs for various vehicles. Some housings are stronger than others, with reinforced versions available for heavy-duty applications like trucks and performance cars.
- Axle Shaft Length: The axle shafts can vary in length depending on the vehicle the rear end was originally designed for. This is important to consider when swapping a 9-inch rear end into a different vehicle.
- Gear Ratios: The gear ratios in the third member can differ widely. Some were designed for fuel efficiency in passenger cars, while others were optimized for performance in muscle cars or trucks.
- Pinion Support: Some Ford 9-inch rear ends feature a stronger "Daytona" pinion support, which is better suited for high-performance or heavy-duty use.
- Aftermarket Variations: Many aftermarket companies produce Ford 9-inch rear ends with upgraded materials, improved designs, and custom options. These can be significantly different from the original factory versions.
How to Choose the Right Ford 9-Inch Rear End
When selecting a Ford 9-inch rear end for your project, it’s essential to consider your specific needs and application. Here are some tips to help you make the right choice:
- Determine the intended use of your vehicle (e.g., street, drag racing, off-road).
- Check the axle width and ensure it matches your vehicle’s requirements.
- Choose a gear ratio that suits your driving style and performance goals.
- Consider upgrading to aftermarket components if you need additional strength or customization options.
- Inspect used rear ends for wear and damage, especially in the housing and gears.
Conclusion
While the Ford 9-inch rear end is a versatile and robust option, it’s important to understand that not all units are identical. Differences in housing design, axle length, gear ratios, and pinion support can significantly impact performance and compatibility. By carefully evaluating your needs and the specific features of the rear end, you can ensure that you choose the right one for your vehicle.
At Kevin’s Autos, we have years of experience working with Ford 9-inch rear ends and other performance components. If you have questions or need assistance with your project, don’t hesitate to reach out to us. We’re here to help!
Frequently Asked Questions
Are all Ford 9-inch rear ends the same size?
We should point out there are three distinct 9-inch axle ends: the late big bearing (Torino) and the early big bearing both take a 3.150-inch od wheel bearing (the difference is in the bolt spacing for the backing plates), the small bearing ends take a 2.834 od bearing with yet a different backing plate bolt pattern.
How do I identify my Ford rear differential?
The most accurate differential identification is provided by the bottom line of the tag number or axle tube stamp. Differential tags can easily be used to identify Dana and Ford differentials.
When did Ford stop using the 9 inch rear end?
1986
The Ford 9-inch is an automobile axle manufactured by Ford Motor Company. It is known as one of the most popular axles in automotive history. It was introduced in 1957 model year cars and ended production in 1986, having been phased out in favor of the Ford 8.8 inch axle.
Is a Ford 9-inch stronger than a 12-bolt?
The Ford 9.000-inch ring gear has a size advantage over the 12-bolt's 8.875-inch ring gear, though not by that much. The Ford's larger ring gear, in addition to its greater offset relative to the pinion, yields a tooth contact area deeper than a GM 12-bolt, making the Ford stronger.
How much power can a stock Ford 9 inch rear end handle?
"They're good only to 400hp max," says Tom at Tom's Differentials. "Anything above that should use today's beefed-up, redesigned, nodular-iron aftermarket cases. They're good to 800 hp, if built properly. The next step beyond that would be the high end, completely redesigned, Mark Williams billet-aluminum housing.
What is so special about a Ford 9 inch rear end?
Unlike most rear differentials that rely on two bearings to support the pinion gear, the Ford 9-inch employs a three-bearing system. This additional support provides several technical and performance advantages, particularly in high-stress and high-torque applications.
When did Ford stop using the 9-inch rear end?
1986
The Ford 9-inch is an automobile axle manufactured by Ford Motor Company. It is known as one of the most popular axles in automotive history. It was introduced in 1957 model year cars and ended production in 1986, having been phased out in favor of the Ford 8.8 inch axle.
How many splines does a Ford 9 inch rear end have?
There are a few 33s mostly spools. Then you have 35 spline or 40 spline. So your 40 spline is going to be spool only. There are posies and 35 spline.
Is a Dana 60 stronger than a Ford 9-inch?
The Ford 9-inch pinion is mounted lower in the carrier and has the greatest hypoid offset, which causes it to consume more power to drive it than the Dana 60 or GM 12-bolt. The Dana 60 has so much mass it too consumes a lot of power to drive (although many say it feels slightly less than a 9-inch Ford).
How do I know what Ford 9 inch rear end I have?
Ford 9 inch rear end identification is easy and can be accomplished with nothing more than a deep socket as a “go-no-go” gauge for the bottom two retaining nuts on the center section. If the socket fits (as shown in our photo below) it is a Ford 8-inch housing.
