The Ruckstell Two Speed Axle Part 1


The Ruckstell Axle was one of the few Ford factory approved accessories for the Model T. Indeed, it is every bit as useful today as it was when introduced in the time just after WWI by Hall Scott. Without a doubt it is the single most useful accessory ever devised for the Model T Ford. Many books and magazine articles have been written about the Ruckstell Axle. No question the best of these books is the one written by Glen Chaffin of Corona, California. It is the “bible” of Ruckstell repair.

Anyone contemplating repair or overhaul of a Ruckstell axle is going to be lost without a good reference book on the subject. Mr. Chaffin’s book is the gold standard of these boks, containing a wealth of accurate information and also a comprehensive history of the Ruckstell Axle, Glover Ruckstell the man, and the Hall Scott company that produced the axle prior to Ruckstell.

The Chaffin book on Ruckstell Axles is available from many sources including Chaffin’s garage and Langs.

Not only did Glen Chaffin literally write the book on Ruckstell axles, his company makes and sells all the parts needed to repair a Ruckstell as well as entire Ruckstell Axle assemblies. Here we see Glen (right) and longtime Chaffin employee Dave Little at the counter in Chaffin’s Garage. The entire Model T hobby owes a giant debt of gratitude to these fellows for all the support they give to us.

Glover Ruckstell’s 1925 pilot license gives us an image of the man behind the axle.

His product was so well accepted by the Ford buying public that Ford carried the Ruckstell Axle (it is mis – spelled “AXEL” on the cover of the Ford parts catalogue!) and repair parts in stock and included the entire Ruckstell catalog within the Ford parts catalog.

In the back of every Ford Model T part catalog is the Ruckstell catalog.

Every piece of the Ruckstell axle is available today only because it is made by Chaffin’s garage.

Our story begins with a Ruckstell purchased at a swap meet. Externally the shifter looks like poo, with signs of breakage and a poor attempted welding repair. The housings look decent, as do the radius rods, drive shaft tube and axles. We suspect the parts inside will be in need of repairs. We are not surprised with what we find.

We took the entire axle apart to inspect the innards. As expected, after cleaning the black goo off of everything, we found some rather frightening repairs and hideously worn out parts. Above (left) the original P141 differential housing had been blown up and then crudely welded in several places. Then it was machined using perhaps a belt sander and an axe. It was so mangled and out of tolerance that when it was installed the differential was locked up if the bolts were tightened fully. Whoever had assembled the axle had left the differential bolts loose so that the differential could work! This would have been a disaster waiting to happen. A new one made by Chaffin was used instead.

The Ruckstell axle has three Hyatt bearings. The one on the left is typical of what we found, it had a cage that had come loose at some time in the past. Whoever worked on this axle last had tightened the bearing by re – swaging the cage support pins. Unfortunately their efforts resulted in the cage being tight, but twisted. This would have resulted in immediate and catastrophic failure of the bearing and / or sleeve.. We replaced all three bearings with new old stock Ford Hyatt bearings like the one on the right.

More monkey business – the P146 sliding clutch gear had been worn out and cracked in the past. Some enterprising knucklehead had welded up the cracks, welded up the gear teeth, and ground the teeth to resemble good ones. Apparently their repair work was good enough to last a while, because the part is now worn quite a bit.

We don’t want the Ruckstell to jump out of gear while driving, and we don’t want to risk having a welded up piece of poo cracking and falling apart to wreck all the other good parts. A new P146 came in the box along with all the other new parts made by Chaffin, ordered from Langs.

By the time we were ready to assemble the Ruckstell over $1200 in new parts were purchased for the job to replace worn out, cracked, and poorly repaired parts. In the photo above you can see we used a brass washer to replace the fiber disc that separates the two axle shafts inside the differential housing.

The new differential housing is assembled with new hardware.

The P159 Ruckstell housing and a new 2518R 40 tooth ring gear are under the differential in the vise. Now the planet gears can be fit onto the differential pins. Using the 40 tooth recessed flange Ruckstell style ring gear with a 12 tooth pinion gear yields a 3.33 to 1 rear axle ratio when in Ruckstell high.

The P145 locking thrust plate is installed on top of the planetary gear set.

The P139 thrust plate is set on top of the Ruckstell housing.

A new sealed P139 bearing is installed.

P146 and P147 are assembled into the Ruckstell assembly. Now we can start all the ring gear bolts.

Note the beveled edge on the P147 is up. A piece of lock wire through the bolts completes the internal assembly process. Note that the ring gear bolts and washers were replaced as part of this overhaul. Ring gear bolts should be thrown away after every use.

To be continued………….

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