A with hydraulics, mysterious parts?

[Steinar]

Hi!
I'm new to the FordBarn, but I read a few interesting writings about a leaking rear main bearing on the model A. So I understand I might get in touch with a lot of skilled and experienced model A folks here.

I'm now doing a brake job on my '31 A. I've owned this car for 10 years now, but never had time for making it road worthy. So it's just been parked out in the barn. The car has once had its brakes converted into hydraulics. I ordered new 39-48 wheel cylinders from SoCal Speed shop, looks great! Today I took off the drums on my rear wheels, but I found parts there, that I had not expected to find. And I don't fully understand their purpose. As you can see from pictures, they are some kind if thin shims going outside the cone end of the axle, probably to make it thicker. As you can also see, one of'em are already teared apart and in need of replacement. If this is the way to go..?


My question: Are we here talking about original parts that really belongs there, or is this what I fear, some home made stuff to maybe compensate for wrong axles inside a too roomy axle-housing? With the drum off, and the mysterious parts taken away, I can make a little movement of the axle-end inside the axlehousing. Is this ok, or should it be absolutely compact?

Any answer would be appreciated!

Steinar

[CWPASADENA]

Install 39-48 Hydraulics on the rear of a Model A requires you to space the drum out to keep it from interfeering with the backing plate.

Some people use a shim on the tapered end of the axle. Others modify the hub and/or drum to space the drum out a little. Still others modify the backing plate.

Using a shim on the taper of the axle is probably the easiest and most common way of solving this problem.

Chris

[steve s]

Originally Posted by Steinar

... Today I took off the drums on my rear wheels, but I found parts there, that I had not expected to find. And I don't fully understand their purpose. As you can see from pictures, they are some kind if thin shims going outside the cone end of the axle, probably to make it thicker. As you can also see, one of'em are already teared apart and in need of replacement. If this is the way to go..?


My question: Are we here talking about original parts that really belongs there, or is this what I fear, some home made stuff to maybe compensate for wrong axles inside a too roomy axle-housing? With the drum off, and the mysterious parts taken away, I can make a little movement of the axle-end inside the axlehousing. Is this ok, or should it be absolutely compact?

Any answer would be appreciated!

Steinar

Behold, the shims! These are definitely not original; they hold the drum away from the backing plate and are needed to stop the drums from locking against the backing plate when the drum is tightened on. I encourage you to get a hold of Dennis Cling's or someone's manual on hydraulic conversions. Dennis recommends grinding down the lip on the backing plate and also the outer edge of the drum. I did all this and still needed to use a shim. Kind of a bummer but not really a big deal; just check the axle nut tightness once in a while. As a kid, I sheared axle keys by running with things too loose. Roadside repairs involved picking the shards out of the wheel bearing grease as best I could, and, once, cutting a new shim out of a tin can I found along the road. THey can now be ordered from Model A parts suppliers. Once you've bought one, you can easily use it as a model for cutting your own. Wise to travel with a spare shim and spare axle key, just in case. You may have to experiment with shim thickness. I think it's better to use one thicker shim than to stack them, although real mechanics are appalled at the use of any such things.

ALso, be aware that there there are two different style backing plates with different adjusters for pre and post-war models, and several models of drums. All four of my drums are different.

Brace yourself for righteous tsk-tsk'ing from restoration purists.

Steve

[Steinar]

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I'm impressed!
Two very good answers even before I had figured out how to upload those images!
And Steve even told me very clear in Norwegian, to keep the shims (behold, norwgian for keep)!

Thanks a lot to both of you!

Steinar