a method or alternate method of performing a rebuild step that will save money but still give acceptable results.
Torque Fasteners—
Illustrates a fastener that must be properly tightened with a torque wrench at this point in the rebuild. The torque specs are usually provided in the step.
Special Tool—
Illustrates the use of a special tool that may be required or can make the job easier (caption with photo explains further).
Performance Tip—
Indicates a procedure or modification that can improve performance. Step most often applies to high-performance or racing engines.
Critical Inspection—
Indicates that a component must be inspected to ensure proper operation of the engine.
Precision Measurement—
Illustrates a precision measurement or adjustment that is required at this point in the rebuild.
Professional Mechanic Tip—
Illustrates a step in the rebuild that non-professionals may not know. It may illustrate a shortcut, or a trick to improve reliability, prevent component damage, etc.
Documentation Required—
Illustrates a point in the rebuild where the reader should write down a particular measurement, size, part number, etc. for later reference or photograph a part, area or system of the vehicle for future reference.
Tech Tip—
Tech Tips provide brief coverage of important subject matter that doesn’t naturally fall into the text or step-by-step procedures of a chapter. Tech Tips contain valuable hints, important info, or outstanding products that professionals have discovered after years of work. These will add to your understanding of the process, and help you get the most power, economy, and reliability from your engine.
AXLE HISTORY AND IDENTIFICATION
Before you embark on the rebuild and start scouring local scrap yards and online websites, it will be helpful to understand what to look for and what to avoid in these axles.
First, you need to understand some fundamentals of the Ford axles to help guide your quest. I have spent countless hours over the years collecting, reading, and studying old shop manuals, supplier reference documents, SAE papers, and even vehicle manufacturer reports and notes. Some of this information is very important as it is becoming more and more difficult to find documentation on axles and differentials that were built more than 40 years ago. I have also spent many hours in scrap yards and visiting and interviewing the experts in this field along with years of building numerous axles myself. In this chapter I share a summary of decades of work on these axles.
As part of my research, I went to renowned Currie Enterprises and gathered one of just about every different 9-inch axle variant. I put together a whole collection of housings and third members. This is a sampling of some of them. Here is a quick visual summary: The 1957 housings do not have dimples on them and have an oil drain plug. The 1958s and 1959s have two dimples on either side of the housing and some have drain plugs. The 1960s to 1967s still retain the dimples but also have an oil level plug in the back cover.
The Ford 8.8-inch axle has a cast center section and the internal components are installed from the rear. There is typically a stamped steel cover that must be removed to gain access to the internals.
This chart serves as a general guideline for axle flange-to-flange width based on different models and production years. I have included the narrow 8-inch axles for reference. The narrowest production 9-inch axle is 56.375 inches. If measuring the drum-to-drum distance, add .200-inch to these values.
An assortment of Ford 9-inch axle stampings is welded together to create the housing. The cast-iron third member is installed from the front of the housing. The third member supports all of the gears and bearings, which allows for easier gear ratio swaps if you have multiple third members.
There is a very fundamental difference between Ford’s 8.8- and 9-inch axles. I reference these axles based on the ring gear nominal outside diameter in inches. The fundamental difference between these axles is how the gears are supported and which end of the axle housing (front or back) that they are assembled from.
It may seem strange to begin by comparing the 8-inch to the 9-inch axle, but there is an important distinction to make since the 8-inch axle is weaker than the 9-inch. Many people are not aware that Ford made a smaller banjo axle and confuse the 8-inch for a 9-inch.
The 8-inch was introduced in 1962 and is found in many lower performance Fairlanes, Mustangs, Falcons, Comets, Cougars, and Pintos, just to name a few of the applications.
There’s
