Wrench Scramble 2015: Project Axle Hell

I love drop-out 3rd member axles for how much they ease parts swapping and fabrication. Most famously Ford’s eight and nine-inch diffs, as well as most solid axles from Japanese truck manufacturers allow the differential to be removed and swapped with simple hand tools. Find a lower-geared, limited slip example in a junkyard or on eBay? You could swap it yourself in half a day and keep your old one for a spare. Secondarily, the entire housing is heavy-gauge steel (as opposed to the cast-iron center-section on a Dana-style one), allowing for easy welding of whatever brackets you need.
There is one challenging part, however: the axle shafts are a press-fit into the ends of the housing, one that can occasionally border on permanent. While reassembling the Ranchero’s rearend, I made a bonehead move and tapped the axle in place without putting the brake backing plate on first. Ok, let’s just yank it out with the slide hammer. Nope. Queue two days straight of torching, hammering, yanking, chaining, more torching and finally Dremel-tooling…

Let’s take a step back: I got a good deal on an 8″ housing and diff, but the housing had been sitting in a side yard for a decade or two. Much wire brushing, air blowing and wiping was required to remove the grass, spider webs and wasp nests inside and rust from the mounting surfaces. Also, all-new drum hardware. Well, almost all-new. Don’t assume you can just pitch all your old drum parts in the trash, as we still needed a few brackets and things from them.

With that out of the way, the order of assembly should be: cut old bearings off axle shafts, press new bearings on, drop the diff in, then drum backing plates, then seals, then axle shafts, then drums. Instead, while check fitting which axle went on which side (they’re different lengths), I got overzealous and just tapped in the driver’s side almost all the way in.
A slide hammer is the standard tool to remove an axle shaft.  and Autozone . In its absence, you can use a brake drum, reversed and  (<–that’s a video). To ease things out, dousing with penetrating oil and heating the end of the housing with a torch helps (though this can cook the non-metal parts of the bearing and any nearby seals).
But my shaft was having none of it. I suspect the fit was so tight because 1) the hole the bearing went into was still rough with corrosion and 2) it’s a brand-new bearing, without any wear off of the internals to loosen up the fit like an old one would have.
A few other methods, according to random guys in forums on the internet: do the reverse-drum trick, but with a wheel, hang it by the shaft and smack the end of the shaft with a hammer to shock it loose and finally use a loop of chain and a bar to make your own slide hammer-like shock loader. I tried all these things and had cuts, bruises, blood blisters and a sore back to show for it.
cut bearing with dremel tool
Finally, I broke out the Tool You Only Use When Something’s Gone Very Wrong: The Dremel® (though mine’s actually a Black and Decker® brand rotary tool). Burning through a whole container of micro cutoff wheels, I nibbled away at the exposed 1/8″ of the bearing, trying to weaken it enough to break the press fit. Just cutting wasn’t enough (I heated and slide-hammered to no avail), so then out came the chisel.
When the first chunk cracked off (and ricocheted around the garage) I didn’t even care if it was going to get the bearing out, it just felt so good to finally actually inflict some damage. More chiseling and more chunks and it was clear victory was at hand. The final act was to cut the remnants of the old bearing apart to get it off of the axle shaft. Alas, Timken RW207CCRA, we hardly knew ye. Until the replacement comes in the mail, that is.

We the Author: