Hot Rods 42-47 Ford Front Axle in Model A

I am building a Model A and have come across a 42-47 front axle. I want to use it along with the wishbones after I split them. I want to move the spring above the axle like a model A would have had and have a question- who makes a spring that will work? I see that the Model A came with a 1 3/4" wide spring and the 42-46 used a 2" wide spring, so I will have to widen the cross member. The big hangup I see is that the center to center on the spring mounts is 40" (or at least that is the dimension for the holes in the axle.) Can anyone give me some direction on what front spring I can use? Or if you have done this, what spring did you use? Thanks!

 

Can you answer why? Basically the late axle is too wide at the perches, and the tires will rub your wishbones. Plus the added expense of the special spring.

An A axle is cheap and easy to find. Save yourself a lot of headache.

 

I think the '46 truck axle is actually an elegant looking axle. At least it has the potential to be. I used one in my champ car because it has several advantages over the Model A axle.
It has a dropped kingpin boss.
It has a depressed center for additional oil pan clearance.
It comes with adequate hydraulic brakes.
It is strong enough to be narrowed .

I narrowed mine 6".
Drilled.
Removed the dual spring pads.
Used a Model A spring with fabricated batwings.
Smoothed.
Gonna paint it silver to look alumnum-ish, like the backing plates.

 

As for why- I like the looks of them with the slight drop. And since I plan on using a big block, I want a strong axle. These look stronger than a Model A especially after you heat and drop an A axle. As for the loss of turning radius, yes the wish bone is 2" closer to the king pin, but there are things that can be done to minimize this. Such as: 1) not pulling the wishbones all the way to the outside of the frame at the back, 2) bending the wish bones so that it allows the wheel to rotate further, and 3) shortening the wishbone. I am not sure of which or what combination I will use. Any idea of what angle the tires can rotate during steering on a normal A?

 

Don't widen the crossmember. U already are needing a different spring, just get one the right width AND length. As for the Model A axle strength, no problem.

Dave

 

33-36 axles dont cost a lot,and can be dropped.The wish bone on the 42-48 has a funny heavy drop to it as I recall. The late front end doesnt look as nice on a open wheel car as the earlier front end.

 

He already made up his mind guys. Don’t try to talk him out of it.

 

Why not just use the Axle and Spring as is? This happens to be a 39-40 unit. Just install an AA crossmember to accommodate the wider spring and you don't need to drop the Axle to get a nice stance. You do however need to do something to get the wheelbase back to where you started.

P.S. I don't think or build like normal home builders.

 

Here's how it looks with No frame kick at all and the wheelbase is exact to Stock Model A. No bullshit!

Look at the Firewall clearance and a manual Fan with 1" space to rad core as needed. Think for yourself and do some Math and save your $$$ for other things.

 

A Model A axle is plenty strong, stronger than it ever needed to be in fact, even after being heated dropped, they are seriously high quality forgings. A big block chevy won't hurt it, not sure where that concern came from. A big chevy barely weighs more than a flathead V8 and there are plenty of examples of A axles supporting everything from bangers to big hemis. But I guess you can go the harder route if that's what you want.

 

If you have totally convinced yourself that you really want to go with a '42-'48 axle; Posies 1025 series springs are made to work spring over on those axles.

Like everybody has said; there are better ways to go about setting up a front end; but hey what do they know.

 

I love this car. If it ever needs a new care taker, let me know!

 

Thank you (and everyone) for the information. But you and Alchemy have decided that my questions mean that I am hell bent on using the axle. I won't know what I am going to do until I do it- and that is a ways away from now.

 

Sorry.

 

Here is one from back in the day; but with modern updates.

Still, better choices could be made.

 

Need something custom and unusual for a spring? Call Atlas Spring & Axle Co. out of Wichita. They're great to work with, reasonable prices and the turnaround was more than acceptable when I needed a new, flipped main leaf for my '29 AA.