I’ve got a few good 42-48 rear axles, and need a few good 40 axles (supposedly 0.85” shorter). I’ve also got a buddy with a CNC lathe in his hobby shop. Has anyone here ever shortened the tapered end of an old Ford axle shaft? Any tips or advice? Wondering about surface hardening, the taper measurements and angle, or any other things learned in your experience.
You might want to add the word 'rear' to the title for extra attention. There have been a few threads about narrowing fronts (which you have proably paerticipated in!)
I'd be interested about those infos also. I have a '46 banjo with a bad axle and a good useless axle that's almost 2" longer than than the 42-48 axles.
Don't folks just swap the axle shafts and axle housings or am I missing something? Meaning that as far as axle housings bolting to center sections and axle shafts fitting spider gears I thought that they were pretty much interchangeable. That and the other end of the housing was were all the differences were but I can be mistaken.
The '42-46 axle assemblies are wider than the more desirable '35-40 year assemblies. As such, the shafts are longer, too, even though they're otherwise the same at each end. Can't put a later axle shaft in an earlier housing without shortening it first. He has more early housings than the corresponding correct-year shafts to go in them.
It should be a straight forward job on a CNC machine once you get it programmed. Pick up the taper from an old axle. On a standard lathe with a taper attachment, it is time consuming but easily done. The keyway is put in on any milling machine. We made narrowed rear ends for sprint cars, track roadsters and dragsters in the old days. There was enough heat treat left in the axle after shortening that it did not have to be re-done.
Thanks guys for bringing this back up. I still haven’t dropped this job on my buddy’s workbench yet, and need to get over there soon as he will begin harvesting corn next month. My main concern I guess is the hardened surface, and cutting through that with the interrupted cut of the keyway. If I need to replace a half dozen bits it might really be cheaper to just go buy the axle from a dealer. If there is no problem cutting through, then maybe we have a handy way to get a more desirable axle. I will post back with the outcome.
I used to work with a guy that did it all the time. He never hardened 'em. He did do a class A finish and add extra keyways to 'em.
I don't know about early axle hardness, but I've shortened and re-splined 9" axles and they were harder than woodpecker lips! Used a carbide burr spinning as fast as I could (until the sparks flew when cutting). If early axles are anywhere near the same hardness, I agree that the keyway created intermitent cut will beat up the machine and cutters pretty hard.
The early axles were forged but I don't think they were hardened. I have cut extra keyways in them no problem.
Not sure,if I look at some stuff another way,do to being in two car things at about the same time ! In the 1950s,I was helping both hotrodders an stockcar racers,plus trying to do my own. How wide a wheel track was,not often adjusted by cutting the axle at all. But by remaking the rims offset or inset. For racing,that could also add corner speed with helpful leftside lbs. Or in the case of hotrod or custom,put a tire in the right spot under a fender,or just look a lot better,from being out too far,or in too far. So learning how change rim centers an outter, was basic. Seems to me,a lot of guys go to way to much work,too end up with,what could of been done,just by redo of rims. Simple is often the best way!!!
Adding on to Mr48Chevy’s post, is it that you need an earlier axle, but just have the later axles available? Or are you narrowing a banjo rear, narrower than the earlier rears? No advice, just trying to see what’s going on.
Dana, sorry but an inch too wide is an inch too wide. Sometimes I do a whole lot of extra work to get a result that 99.99% of people will never notice. A simple wheel change isn’t possible when I already have a certain wheel in mind.
Budget, I want the standard ‘40 Ford width, am going to be assembling a few of them, and don’t have enough. Seems when you pull a rearend apart you usually find one bad axle.
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