Converting the stock Model A front axle?

[Paul B]

Cool information here, seeing as I dropped in to ask if a stock Model A axle and spring was man enough for a SBC, but it sounds like it is.

How about popping a few holes into the stock axle, for looks? Is that okay, not going to weaken anything? I wouldn't go too big, maybe 3/4" diameter.

Mine came with no hubs or brakes, so I had to convert some horrible metric disc hubs to suit. looks pretty naff really, but seems to work. if I did it again I'd buy a kit from Speedway. When I work out the cost of parts, machining and man hours it is not really worth doing it myself, apart from the fun, and the experience.

[Thunder]

Look what I got last weekend from a fellow rodder (thanks Henry!):



Conversion from the 11" mechanical Model A brake to a 11" self energizing Bendix style hydraulic brake. Just what I was after!

The mounting holes for the spindle are redrilled, the wheel cylinders sits not at the top as the kingpin top bearing is in the way. The wheel cylinder is a 1" Willys Jeep one ('46-'52). I still have to find out where the other hardware came from. I will not use this setup to trust my life to as the alignment and welding is a bit too much rat rod for me. With a bit of measuring and engineering I hope to be able to fit the wheel cylinder above the kingpin. Much better for looks and for bleeding the brakes.

[langysrodshop]

Look what I got last weekend from a fellow rodder (thanks Henry!):



Conversion from the 11" mechanical Model A brake to a 11" self energizing Bendix style hydraulic brake. Just what I was after!

The mounting holes for the spindle are redrilled, the wheel cylinders sits not at the top as the kingpin top bearing is in the way. The wheel cylinder is a 1" Willys Jeep one ('46-'52). I still have to find out where the other hardware came from. I will not use this setup to trust my life to as the alignment and welding is a bit too much rat rod for me. With a bit of measuring and engineering I hope to be able to fit the wheel cylinder above the kingpin. Much better for looks and for bleeding the brakes.

That looks to me just like a standard 11" Ford setup ??? Taking into consideration the caster angle in the axle the wheel cylinder can't be a problem ??? this pic explains what I mean

[Thunder]

Steve, what I try to achieve is to have hydraulic brakes in combination with the original (cast iron) Model A drum and spindle. I want to run '35 wire wheels. The original model A back plate has a recess of approx. 45 mm to get the center of the rim as much as possible in the pivot point (spindle bolt) to avoid scrubbing of the tire when the wheel steers. The F100 back plates are flat, they do not have this recess. The wheel cylinder of the Argentina back plate sits above the spindle bolt as you can see in the picture:


This is the way the back plate was mounted.


This is the way I would like it to be (the cylinder at 12 o'clock).
As it is it leaves not enough height for the ball bearing that sits on top of the Model A spindle.
Do you know a solution for that? Are there lower ball bearings available?

[rem]

The later Ford spindles ('37-onwards) have the bearing between the bottom spindle boss and the axle, but changing to those spindles would defeat the object of using the Model A brakes? I think all the 'mechanical brake' style spindles have that bearing on top of the axle.

[Thunder]

The later Ford spindles ('37-onwards) have the bearing between the bottom spindle boss and the axle, but changing to those spindles would defeat the object of using the Model A brakes?

Yes, it would. If that bearing can't get lower, could I use a smaller diameter brake cylinder, say a 3/4" one? Those are on the back brakes of '46-'52 Willys for example.

[langysrodshop]

Sue's A has 32 spindles with bearing on the top, 40 ford brakes went straight on with a small adapter on the spindle to take the larger hole in the 40 backplate, looks like a piston ring

[langysrodshop]

Here ya go

[Paul B]

You can always get that conversion needle roller bearing that goes under the beam. I used to have a part number somewhere, meant to order some....

Not sure if anybody uses them, or is there any reason why not too? That idea of the whole shebang 'hanging' on the above bearing seems a little odd to me.

[rem]

Is the needle bearing kit for the early spindles? Stock, there is only room for a shim in there (see the red one above). It always struck me as odd that the kingpin head was supporting the whole front, but I guess they had a good reason for it.

[Paul B]

I think mine has about 3mm space, but can't remember now. It wouldn't be a big issue to grind/mill some material off the top of the beam to give enough room. A needle thrust roller and two proper hardened washers wouldn't be more than a few mill thick.