Chapter 3: Rebuilding the Rear Axle
Common Axle Problems
Vehicle Preparation
Axle Disassembly
Cleaning and Inspection
Axle Reassembly
Summary
Chapter 4: Factory Limited-Slip Differentials
Determining Limited-Slip vs. Open Differential
Tear-Down Process
Checking the Parts for Wear
Rebuild Process
Final Assembly and Performance
GM-Style Limited-Slip Differential
Cone-Style Limited-Slip Differential
Ford Mustang Differentials
Summary
Chapter 5: Aftermarket Differentials
Limited-Slip Differentials
Open Differential
Spools and Mini-Spools
Lockers
Helical Technology
Viscous Control Technology
Torque Vectoring
Summary
Chapter 6: Ring and Pinion Gears
Torque Multiplication
Hypoid vs. Spiral Bevel Gear Systems
Hypoid Mounting Dimensions
Tire Size and Gear Ratio
Gear Manufacturing
Gear Materials
Gear Tooth Geometry
Disassembly and Assembly of Ring and Pinion Gears
Setting Gear Contact Pattern
Ring and Pinion Break-In Procedure
Speedometer Accuracy
Summary
Chapter 7: Axle Shafts
Axle Shaft Function
Axle Shaft Geometry and Nomenclature
Materials and Manufacturing Methods
Spline Details
Bearing Surfaces
Flange, Lug Studs and Nuts
Summary
Chapter 8: Driveshafts, Universal Joints and Pinion Angle
Driveshaft Considerations
Retention Methods
Sizes
Vibrations
Joint Angles
Lubrication
Summary
Source Guide
Over the past 50 years, Ford, Chrysler, GM, and the aftermarket have developed and released a variety of differentials, axle shafts and housings, and driveline components. Finding and selecting the right combination of driveline components for a particular high-performance car is no easy task because the myriad of equipment and seemingly limitless options can appear overwhelming. And, I can’t think of a better person to wade through it than Joe Palazzolo.
I first met Palazzolo while attending his SAE driveline course. Back then I was the Technical Director at Car and Driver magazine and I wanted to learn exactly how modern drivelines work. There’s a lot of confusion out there, even among car-company employees and we wanted to be able to explain to our readers why some systems are better than others. Plus it’s fascinating stuff.
While we’ve come a long way since Positraction, that doesn’t mean your Ford nine-inch rear end will be shelved anytime soon. Actually, most of the driveline principles that dictate driveline function and operation haven’t changed much. So what you’ll learn in this book will be valuable, no matter what kind of car you’re working on.
So what will you learn? Through pictures, diagrams, and Palazzolo’s clear explanations, you’ll get the basics like the difference between CV and universal joints and what exactly is a hypoid gear. The book also goes much deeper into service techniques, modifications, and general maintenance. Plus, where else are you going to find the difference between face milling and face hobbing? I’m sure writing this book wasn’t easy, but he’s definitely up to the task.
In my line of work I quickly learned to differentiate the engineers who had cursory knowledge of a particular subject from the ones with a deep understanding. Palazzolo’s in the latter group. The guy’s not only a degreed engineer, but also an ASE master technician so he has the practical background that too many engineers lack.
There are many books out there that touch on some of these subjects, but not one that encompasses everything like this one does. It’ll certainly be a part of my reference library.
I’ve learned a ton from Palazzolo and I’m sure you will too.
– Larry Webster
Detroit Editor
Popular Mechanics magazine
This project has been an interesting journey for me. I learned that there is so much information and new things (and some old things) about axles. I realized that I learned so much by putting my experiences into text. I also made many new friends and strengthened relationships with old ones. I sincerely thank everyone who helped, either directly or indirectly, with the writing of this book.
Tony Nausieda for the opportunity to pursue this book, reviewing draft text, loaning me hardware and even letting me crawl around his barn at sub-zero temperatures to get the last few coveted photos. We all should be so lucky to have such a great friend.
Randy Golda and James Walker for taking the time to review the draft at the proverbial eleventh hour.
My longtime friend, Ward Bowerman, from Torsen for taking his personal time to review Chapter 4 and provide valuable insight and encouragement.
Jason Bock was instrumental with Chapters 4 and 6 and reviewed the draft text and all of the in-depth discussions about theory and practice of assembly steps and differential function.
The entire team at Drivetrain Specialists, specifically Sandy Rissman and Rob Gutowski, for treating me like part of their extended family and allowing me unrestricted access to their shop, parts, and mechanics. Without their openness and cooperation, this book would have never been possible. There was never a time when they did not accommodate any of my requests for support and help.
The countless folks who willingly shared comments and photos for inclusion: Ralph Traycoff from Auburn Gear, Darlene Oleksik from Eaton Corporation, and the teams at GKN Driveline, Strange Engineering, and Winters Performance.
Steve Wesolowski and his team