Juice brakes - gap between hub and drum?

M

Marcus J

Junior Member
I'm going to mount 1940-48 juice brakes on my Model A with 1932 wire wheels. With the original drums the outer rim of the wheel hub rests squarely against the side of the drum, however with the type of new 1940-48 drums I'm thinking of buying there is a gap. This does not seem right. I will drive the car in dirt track races and want full support of the hub, or is this not necessary? Does anyone know? Would original 1940-48 drums work better, or is it the same issues also with those?
 
I had this problem with my Town Sedan too. I used .010 shim stock and made a cone shaped shim. Then I trimmed the shim down to the circumference so it would just fit around the key. I reassembled the hub and it worked perfectly. Then I discovered them for sale in Bratton's. Hey I didn't know! The real question is why doesn't it work (fit) or it works for some and not for all?
Terry
 
Marcus J said:
... With the original drums the outer rim of the wheel hub rests squarely against the side of the drum, however with the type of new 1940-48 drums I'm thinking of buying there is a gap.
This does not seem right. I will drive the car in dirt track races and want full support of the hub, or is this not necessary? Does anyone know? Would original 1940-48 drums work better, or is it the same issues also with those?
Click to expand...

Marcus,
There are two separate issues involved here.
I believe your post refers to the extreme outer circumference of the wire wheel hub contacting the brake drum (issue 1) and not the wheel/drum contact points next to the wheel stud (issue 2).

Issue 1. From the factory, the 32 - 35 wire wheels contacted the drum at the outer circumference of the wheel hub. There will be a gap at this point when using the wire wheel with some (maybe all?) of the repro 40-41 drums. I measured this gap at about 0.070" with the Lincoln repro drums. Some OEM drums seem to eliminate the gap (based on my limited sample).

I sympathize with your desire to have "full support of the hub" especially given your intended use. However, there have been 100s of cars with this wheel/drum gap running around for decades seemingly without problems. Of course, most are in much less demanding service that you intend for yours.

Issue 2. (This issue is not obvious when you just plop the wheel on the 40 - 41 drum.) There is a need to add a spacer ring to the wheel so that the wheel will contact the flat mounting surface of the later drum (either repro or original). (The OEM 32 - 35 hub/drum contact points were not flat and the wheel contact pads near the stud reflect this.) The responses you've received mostly address this issue.

Hope this helps.
John
 
Forums like this one, with such helpful people are great - Thank you guys! John, you nailed it. It was issue 1, but it was a bit difficult to explain. Now I feel reassured and will order the Lincoln style drums, and hub center spacers. To be on the safe side I will also make spacers for the outer circumference.
 
Marcus,
Since I'm unaware of anyone actually making/using a spacer for the outer circumference, I'm very interested in learning how it works out. So, I'd very much appreciate it if you'd send me a PM with a photo, etc. (Since I'm usually on the V8 forum and rarely on the Model A forum, I probably won't see it if/when you post it here.)
Thanks in advance,
John
 
im not clearly understanding the problem . I have '42 hyd brakes on my coupe with 16" wires . no problems . they make a kit for the fronts (moves the drum out to clear )
& I use 2 shims on the rear axle for drum clearance there . you can get the kits & shims from most venders .............
 
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