Wheel spacers

8EL

8EL

Senior Member
In mounting the rear hubs and drums on my coupe, it appears that the reach from the hub flange and the depth of this mating surface on the drum are basically the same at 1.375". Resulting in the drum locking up when the rim is mounted and tightened on it's studs. There have been new axles installed in the process of rebuilding the differential. Also the backing plate mounting flange has been turned down as Brent Terry had recommend, which I thought was an excellent idea as it would move the brake shoes away from the drum, my thought being no need for shimming the taper on the axle. The leading edge of the brake shoes have been chamfered as recommended, the only thing different here is that the shims on the axle taper have not been used.

Speedway sells a spacer (which I have used) to shim the rim away from the drum face providing the necessary clearance allowing the rim to be tightened up bearing on the face of the drum as intended. These spacers also have a flange on the hub which is installed facing out to provide a shoulder to bear against the rim to carry the load of the car, instead of hanging the weight on the wheel studs. They measure about .110" which I am thinking to install on the hub flange to space the drum away by this amount from the brake shoes.

I could machine this hub off to make it just a flat .110" spacer and provide the clearance needed, but I would rather just buy a flat spacer of this thickness if possible, or I could make a couple of them if I had too. I do not want to use the shims on the axle taper, this being a critical mounting surface it should be mated to its taper without need to shim it out.

Is anyone aware of this type of spacer being marketed for such a purpose?
 
This is what I had in mind, but the hole center is incorrect. My hubs are on a 5.5" hole center line.
 

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This is a confusing post because the wheels should not effect how the drums sit and how close, or how much interference there is with the backing plate.

Stock wheels? The Model A wheels were designed to fit to 3 places, the hub, at the studs, and at the drum. The Service Bulletins shows where they sit on the hubs and drums, page 108 of the book. The early hubs and wheels were different and the different styles cannot be intermixed. This may be where the problem is coming from.

New axles are a good idea, but the taper in old hubs are usually worn which will cause an interference problem. I would advise trying the sheet metal shims that wrap around the tapered part of the axle. A spacer will defeat the way the Model A wheels are designed to fit to the hub and drum. Again, see the Service Bulletins.
 
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Brake shoes "centered?" Have they been ground to fit the curve of the brake drum?

Are the new drums on new hubs? Old hubs tend to be "stretched" where they have repeatedly been driven over the axle taper.

New axles SHOULD be the best way to go - but there have been reports that the new differential gear are welded to the new axle shaft - and these have had reported failures. (Original axles are one piece.)

Agreed on the taper shims but it may depend on how you report on my query above.

Joe K
 
I must be missing something here.The drum is swaged onto the hub,there is no reason for it to get any tighter by tightening the lug nuts.Are the drums swaged on? Is all this Model A or other year stuff?
 
nkaminar said:
This is a confusing post because the wheels should not effect how the drums sit and how close, or how much interference there is with the backing plate.

Stock wheels? The Model A wheels were designed to fit to 3 places, the hub, at the studs, and at the drum. The Service Bulletins shows where they sit on the hubs and drums, page 108 of the book. The early hubs and wheels were different and the different styles cannot be intermixed. This may be where the problem is coming from.

New axles are a good idea, but the taper in old hubs are usually worn which will cause an interference problem. I would advise trying the sheet metal shims that wrap around the tapered part of the axle. A spacer will defeat the way the Model A wheels are designed to fit to the hub and drum. Again, see the Service Bulletins.
Click to expand...

Guess Ill start here. The flange on the axle housing is the mounting surface for the backing plate. The shoes mount on the backing plate, that flange has been cut down, moving the shoes away from the drum. The distance between the drum and the shoe is determined by the tapered bore in the hub that mates with the axle, and the mounting plane of the backing plate. For now lets leave the wheels out of the consideration. So then if I install the hub on the axle torque it to the specified 125 pound/feet value, slide the drum on the hub (I will get to that also), and tighten the lugs to fully seat the drum, the wheel will not turn. This is because the clearance between the shoe and the drum are insufficient. Installing shim stock on the axle taper would increase this clearance, but as these are brand new axles I was hoping the clearance would be sufficient. The other option I was contemplating here was to install a shim between the hub and drum mounting surfaces. This would also solve the clearance problem, but it will also diminish the engagement of the hub with the mounting hole inn the drum. The drums being used are;
Speedway Motors | #91065400
12 x 2 Brake Drum for Bendix Style 1937-48 Ford Brakes

The Hubs came with the car, which appear to be early ford 5 on a 5.5" center line, that were originally swedged to the drums....I will get to that also.
 

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Joe K said:
Brake shoes "centered?" Have they been ground to fit the curve of the brake drum?

Are the new drums on new hubs? Old hubs tend to be "stretched" where they have repeatedly been driven over the axle taper.

New axles SHOULD be the best way to go - but there have been reports that the new differential gear are welded to the new axle shaft - and these have had reported failures. (Original axles are one piece.)

Agreed on the taper shims but it may depend on how you report on my query above.

Joe K
Click to expand...

So these are new drums indicated below, new shoes, old hubs, but appear quite serviceable. These are 42-48 backing plate so there are no eccentric adjusters, but rather fixed anchor pins on the bottom. The axles are first quality made in this country by Mark Auto Co, Layton, NJ

The shoes were installed (have pictures but not yet downloaded to this drive) on the anchor pins mated with the wheel cylinder and then the top return spring was installed. The top adjusters were turned in and the drums installed. The rest has been covered here I think.....So how would I be centering the shoes? The old Motors manuals that I have from the forties are not outlaying this procedure....
 
Could not upload the rich text format which I had saved originally as. The plain text file looses much formatting, but can still be read. Send m an email if you want and I will send the .rtf version......
 
Centering and arcing is referring to stock A brake components.Didn't see any reference to later parts in your first post,so until you mentioned the later parts in a later post I think everybody assumed you were dealing with a stock A.Makes lots more sense now.
 
Joe K said:
Brake shoes "centered?" Have they been ground to fit the curve of the brake drum?

Are the new drums on new hubs? Old hubs tend to be "stretched" where they have repeatedly been driven over the axle taper.

New axles SHOULD be the best way to go - but there have been reports that the new differential gear are welded to the new axle shaft - and these have had reported failures. (Original axles are one piece.)

Agreed on the taper shims but it may depend on how you report on my query above.

Joe K
Click to expand...

Rear brakes as installed...
 

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Keith True said:
Centering and arcing is referring to stock A brake components.Didn't see any reference to later parts in your first post,so until you mentioned the later parts in a later post I think everybody assumed you were dealing with a stock A.Makes lots more sense now.
Click to expand...

The Lockheed brake is much improved over the stock mechanical brake on the A. The safety of the car is improved, specially now as people will ride 3' behind one another at 80 MPH. My car had Ford lockheed brakes installed when I bought it, one would say it is a hybrid having 39-41 fronts and 42-48 rears. I would lean toward they used what they had, it will work well when finished, the rest of us would lean toward Frankenstein. In all honesty, for the time and money spent to make this all right, if I had it to do over I would go with the Bendix self actuating style brake. It was superior in braking effort to the Lockheed due to it's design, and much, much simpler to set up properly. When I worked in the garage I would do 2 complete brake jobs a day. This included turning drums, and rebuilding (EIS kits, popular) wheel and master cylinders with new shoes, hardware kits and hoses.
 
Oh. So I retract all I said about the stock hubs, drums, and wheels. I still think adding shims at the axle taper would help. You said that you have old hubs. They could be stretched or/and worn.
 
This all said then, and the issue at hand now known, how would it be best then to increase this clearance? I really do not want to add shims to the axle's on their taper. Leaning toward shimming the face of the hub out. This will move the drums contact out somewhat from the hub. But on a 2,400 pound car is this really a problem? I recall when I put Centerlines on my Starfire the hole in the rim was larger than the axle hub, therefore putting all of the load of the car (almost twice that of the coupe) on the wheel studs. Of course inquiry was made with the manufacturers engineers who informed me that this was not, and would not be an issue. The specs on the ARP fasteners did bear this out, so I have ran them making many nearly 150 MPH passes without issue of any sort....obviously as I am writing this. The Dorman studs used are not of aircraft grade steel like the ARPs, but none the less for the application are of very good quality. I suspect that they are more than adequate....Comments constructive criticisms and/or concerns please....
 
I'm using spacers similar to the ones that you envision using to adapt modern wheels to Model A drums. While it's not exactly the same application, it's working well so far --- after about 1,000 miles. It certainly seems like the easiest approach given your situation. These spacers are aluminum and lend themselves to some pretty simple sanding to establish the thickness needed. Seems pretty low risk to try. That's my vote -------------
 
Keith True said:
Centering and arcing is referring to stock A brake components.Didn't see any reference to later parts in your first post,so until you mentioned the later parts in a later post I think everybody assumed you were dealing with a stock A.Makes lots more sense now.
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Indeed. HAMB content for sure. Someone over there (I realize there is a lot of "cross-over") will have done EXACTLY what you're doing.

It's a big hobby. I'm glad for those who set aside their Model A parts since that leaves so much more for me.

One is reminded of last year's front axle assembly that was set aside by someone building a "gasser." Boxed aftermarket frame. And decided to go the Sacramento route. Nice axle - straight - and didn't need much to work it up for use.

Joe K
 
bruceincam said:
I'm using spacers similar to the ones that you envision using to adapt modern wheels to Model A drums. While it's not exactly the same application, it's working well so far --- after about 1,000 miles. It certainly seems like the easiest approach given your situation. These spacers are aluminum and lend themselves to some pretty simple sanding to establish the thickness needed. Seems pretty low risk to try. That's my vote -------------
Click to expand...


Bruce, are you using this spacer between the hub and the drum, or the drum and the rim?
 
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