Ford Differentials. Joseph Palazzolo

two of the most common Ford axles (8.8- and 9-inch) and the exact details on how to disassemble, inspect, upgrade, and build these axles into high-performing and reliable units. However, many of the principles can be applied to most other axles. I have performed hours of rebuilds and modifications of these units along with research and interviews with the experts to understand what works and what does not. Many magazines tend to skip over the modifications required to make an aftermarket part fit correctly. After reading this book, you should be better prepared to complete your Ford axle project.

      My first experience repairing axles was with the front axle on a 1981 Buick Riviera. Like many of the parts of the car that I had previously worked on, it came out of necessity and curiosity. The necessity was more financial, as I could not afford to have a mechanic repair my cars and the curiosity was that I really wanted to understand how these things work.

      The Riviera has a north/south powertrain layout with an Oldsmobile 350 V-8, a unique transmission, and an independent-style front axle next to the engine’s oil pan. Numerous Mustang 7.5- and 8.8-inch rear axles and then GM 10- and 12-bolt axles quickly followed it. There have been countless repairs of vehicles since then including quick-change-style axles and all of the Dana variants, including Corvettes and Vipers.

      Have a conversation with any muscle car or street rod enthusiast, and when it comes to axles, most will swear by the Ford 9-inch axle. It has been the go to axle for decades. Even with production stopped more than 25 years ago, this axle still has a place in many performance cars and trucks. It seems that rear axles are a bit of a mystery even to the most veteran of mechanics. While we are comfortable with engines, brakes, and suspension, few are comfortable working on and setting up axles at home. I am not certain if this is because most axles only require minor maintenance to be trouble-free, and therefore, mechanics don’t get enough practice to stay sharp or if it is from a bad experience of working on an axle. The latter is probably why most shops do not want to work on them and leave them to the specialists or experts.

      My intention is to help you understand the function of and how to rebuild the Ford 8.8- and 9-inch axles. With this knowledge, you can decide whether you want to tackle your axle repair yourself or at least understand what is involved and how to find a good shop to perform the work for you.

      Axles are the only part of a car that utilize a hypoid gear set. These gears require some special training, tools, and skill to work on correctly. That being said, it is not beyond most competent mechanics and even the enthusiast to repair or rebuild axles. As with any car repair, this requires organization, time, and patience. But with these in place, most mechanics can achieve great results.

      When it comes to gear ratio, this book should help you decide if 4.10s make sense based on your vehicle’s transmission ratios, tire size, and intended usage. It will also help you decide if you really need 35-tooth spline axle shafts.

      You need be sure that the upgrades you make meet your end objectives and don’t just waste your hard-earned time and money. I have received countless calls and emails from people who purchased the wrong hardware, have it in their car and are unhappy because someone gave them bad advice. It is so important to understand your project and select the correct components to have your desired outcome.

      I provide information that you won’t find in a common shop manual while still covering the shop manual fundamentals. I want to be as comprehensive as possible but I cannot include every single piece of information on these Ford axles. I have, however, tried to make certain that all of the facts in this book are correct.

      So when someone provides you with good advice like “a Ford 9-inch with 4.11s is the best way to go for your car,” take it with a grain of salt and do your own research to get the best solution for your needs. The key is to enjoy the work and with the help of this book, you will achieve great results.

WHAT IS A WORKBENCH® BOOK?

      This Workbench® Series book is the only book of its kind on the market. No other book offers the same combination of detailed hands-on information and revealing color photographs to illustrate differential rebuilding. Rest assured, you have purchased an indispensable companion that will expertly guide you, one step at a time, through each important stage of the rebuilding process. This book is packed with real-world techniques and practical tips for expertly performing rebuild procedures, not vague instructions or unnecessary processes. At-home mechanics or enthusiast builders strive for professional results, and the instruction in our Workbench® Series books help you realize pro-caliber results. Hundreds of photos guide you through the entire process from start to finish, with informative captions containing comprehensive instructions for every step of the process.

      The step-by-step photo procedures also contain many additional photos that show how to install high-performance components, modify stock components for special applications, or even call attention to assembly steps that are critical to proper operation or safety. These are labeled with unique icons. These symbols represent an idea, and photos marked with the icons contain important, specialized information.

      Here are some of the icons found in Workbench^® books:

       Important!—

      Calls special attention to a step or procedure, so that the procedure is correctly performed. This prevents damage to a vehicle, system, or component.

       Save Money—

      Illustrates 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