There are three words in the hot rod vocabulary that can remove all doubt as to whether or not a car is worth a second look: quick-change axle. We've made every part of the car extreme so many times that we're pretty much inured to it. But for some reason a weird-looking casting that uses obsolete components and makes noise that would ordinarily annoy the hell out of us still gets us all giddy inside. Never mind the fact that 99 percent of us would never ever change the gears in it. It's cool just sitting there.
But there's something about a quick-change that's equally intimidating too! For the most part the critical interface between the ring and pinion gears in any axle requires specialized tools and experienced hands. And with a quill shaft and twice the bearings and gears, a quick-change axle looks that much more intimidating.
That fear is largely unwarranted. The heart and soul of a quick-change axle is the Ford banjo. Ford's designers created an axle as simple as it was tough, and as a result, the most "specialized" tooling required to rebuild a banjo is a large socket and a dial indicator. What's more, the parts that make a quick-change different from a conventional banjo axle are simpler yet.
While building the axle is fairly straightforward, there are a few things that make installing one in a hot rod a little bit trickier. Our Man at the Mile High, Frank Wallic, is installing one in his dream-car Deuce roadster and he encountered a few of these quirks. Those of you who've seen his bomber-inspired aluminum components know he's more than capable, so when he told us that he shot the installation we were more than willing to relay his notes and findings.
There's another reason we wanted to show this install. First off, the quick-change center (gear case) he's using is a new-old-stock Halibrand Engineering piece, cast when Ted Halibrand still ran the company. Ted sold the company 30 years ago, making this one old--and likely one of the last N.O.S pieces in existence. Veteran hot rodder and racecar restorer Bill Riedel got it among a bunch of boxes that made a Midget race car, and when Frank told him he was in the market, Bill made it available. What's more, Bill offered to personally walk Frank through the assembly.
We're going to repeat the general process and dispense a few tips, but we're doing it more as a means to inspire and empower you to do your own. We'd rather not bore you with the exact details and variations. That's the job of a Ford technical manual, so to tackle the job properly we advise finding one.
But trust us--building the one part that can transform a ho-hum beater into a hot rod really is simpler than you thought.
The centersection Frank bought had an open-drive snout on it, which certainly opens the door to transmission choices. But it also opens the door to a potentially dangerous pitfall.
It has to do with the suspension Frank runs. Following common practice, he split the radius rods, equipped them with bushing ends, and used them to locate the rear axle. The design is called a two-link and is the ladder bar's ancestor. But without the driveshaft housing to control the axle's reactive force (wrap-up) the radius rods must bear it and the thrust load. That's a load they were not designed to bear, and they can fail with disastrous results.
There is an elegant solution, though. A rod that connects a point high on the axle to the leading end of the radius rod greatly increases the design's capacity. It basically transforms a radius rod into a truss which is highly capable of bearing a great torque load. It's the premise behind the triangular shape of the ladder bar. In fact, this design is not exclusively Frank's; Hot Rod Works (Nampa, ID) has offered a kit for some time that achieves this same result. And to be honest, it's probably not the first either.
This quick-change is one produced...
This quick-change is one produced when Ted Halibrand owned Halibrand Engineering. It's easily 30 to 40 years old but it's brand new. Understandably Frank was nervous building it himself, so he entrusted hot rodder/restorer veteran Bill Riedel to help.
Frank emphasized attention...
Frank emphasized attention at teardown. "By the time bearings get this old, they're usually pitted," he said. "Mine sure were."
He also said to scrutinize...
He also said to scrutinize the keyways in the axle ends, as a sheared key and spun axle can cause a lot of damage.