Are all Ford 9-inch rear ends the same?
No, not all Ford 9-inch rear ends are the same. While the Ford 9-inch rear end is a popular and widely used differential, there are several variations and differences between the various models produced over the years.
Understanding the Ford 9-Inch Rear End
The Ford 9-inch rear end is a robust and durable differential that was used in a wide range of Ford vehicles, from muscle cars to trucks, from the late 1950s through the 1970s. It is known for its strength, reliability, and ease of modification, making it a popular choice for high-performance and off-road applications.
However, despite its widespread use, the Ford 9-inch rear end is not a single, uniform design. Over the years, Ford made several changes and improvements to the 9-inch, resulting in different versions with varying features and specifications.
Key Differences Between Ford 9-Inch Rear Ends
- Ring Gear Size: The most significant difference between Ford 9-inch rear ends is the size of the ring gear. The ring gear is the large gear that the pinion gear meshes with, and it determines the overall strength and capacity of the differential. Ford 9-inch rear ends were produced with ring gears ranging from 8.8 inches to 9.75 inches in diameter.
- Axle Tube Diameter: Another key difference is the diameter of the axle tubes, which can vary from 2.75 inches to 3.25 inches. The larger the axle tube diameter, the stronger the rear end.
- Differential Housing: Ford 9-inch rear ends were produced with different differential housing designs, including the standard "banjo" style and the more modern "third member" style.
- Gear Ratios: The gear ratio, which determines the balance between torque and speed, can also vary between different Ford 9-inch rear ends. Common gear ratios include 3.00:1, 3.50:1, 4.11:1, and 4.56:1.
These differences in ring gear size, axle tube diameter, differential housing, and gear ratio mean that not all Ford 9-inch rear ends are interchangeable or compatible with each other. It's important to carefully research and identify the specific model and features of the Ford 9-inch rear end in your vehicle to ensure proper fitment and performance.
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.
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 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 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.
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.
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.
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).
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 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.
