Guys, Do any of you have a 1946 - 48 Ford car front backing plate AND a 1953 - 56 F100 front backing plate? I need a measurement for both on how big across they are so I can figure out what I have on my roadster. I have what I thought were F100 brakes and backing plates. I think I had a bad hub so I bought speedways replica 40 hubs which they claim will work with F100 brakes. No they don't. The diameter where the F100 drum registers on their hub is .100" larger in diameter than the F100 drum hole. Possible solutions, machine the drums registration hole out by .100" or turn their hub down by .100". Neither is my first choice. So I talk to them and they tell me their stuff should work. So I bite the bullet and buy their drums, which they claim will work, only to find they will not clear the backing plates and seat properly on their hubs. The only thing I can figure at this point is I have F100 backing plates and their drums and hubs are made to work with car backing plates ONLY or their backing plates ONLY. I had some 47 Ford car backing plates but passed them on to a friend when I thought I had this all solved. Any help sorting this shit out would be very much appreciated. Gordon
The early Ford brakes are 12” and F-1 and F-100 are 11”. I don’t think anything exchanges between them.
Thanks Alchemy. I just measured my backing plate and it is 12 inches across. The brakes were originally sold to me as 53 F100 backing plates, hubs, and drums. I ordered all new shoes and hardware and drums and rebuilt everything and they have been working fine so I assume all parts were proper F100? Speedways drum doesn't work with this backing plate for certain and their hubs registration diameter is .100 to large for the drum I have. Their hub measure 3.250" dia and my drums hole measures 3.150". I spoke with their rep and he said their stuff would work with F100 stuff and 12 inch backing plates. It says it works with the car stuff too but I don't see how it could.
Sounds like you have F-100 stuff from the #s and there is no way Speedway's repop early Ford hubs or drums are compatible.
Thanks Rich B. That is what my drums and hubs measure exactly. As I noted before all this stuff was working properly. The only reason I wandered into this problem was I was trying to chase down a wobble I had and noticed that my DS hub was machined off center by .100" so I wondered if the off center rotating mass would add to a wobble problem. Decided to see if I could find new replacement hubs, and couldn't, and ended up at Speedway. After reading the info on their website and talking to a rep I was assured they would work with F100 brakes and 12 inch backing plates. As I am finding out they are full of shit.
A tenth is huge for a Ford hub to be miss-machined, is it possible the flange is bent from hitting something? Maybe check the bare hub with a dial indicator. If not too far out, the flange can be trued up on a lathe.
Rich B I saw it by setting up an indicator and then spinning the hub on the axle. As it spun I could see almost .100 wobble from one side to the other. Hard to see in the pic below but if you look at the bottom of the pic near the edge of the seal and then look at the top of the pic near the seal you can see the difference.
The 12 inches is the inner diameter of the drum, not the measurement across the outside of the backing plates.
Alchemy I have taken a few pictures so I can show what I am working with. The stuff was sold to me as 53 to 56 F100 brakes. My drum measures 11" inside dia. The registration hole measures 3.15" dia.. The backing plate for the F100 setup I have measures right about 12" outside to outside. My hub looks to me like an F100 one. I bought a bearing kit to adapt F100 hubs to my 47 spindles from Speedway and that works as it should. When I ordered brake parts I ordered 53 to 56 F100 brake parts from Napa. Shoes, wheel cylinders, hardware, and drums. Don't know if this will help or not? Speedways drum measures 12" inside by the way. There doesn't seem to be a resolution using Speedways hub and drum that I can see unless I also buy their loaded backing plates, which I am not going to do as everything I have has less than 350 miles on it. If car backing plates are a little smaller diameter that the F100s Speedways drum might clear it and work but then what do I use for brake parts? I think at this point instead of pissing away good money after bad I am returning all the Speedway stuff and just replacing my old out of round F100 hub with another old F100 hub and taking my chances it will be a good one. That way I can at least use what I already have with the minor additional expense of another used F100 hub. I appreciate any ideas or help you might have.
Should not be that hard to get: https://www.ebay.com/itm/3346258196...DJQlUbTgO+K8ykd714dYe7uuc=|tkp:Bk9SR-KQpdOeYQ
I found a set of used hubs already guys but was hoping to not have to use old possibly bad parts again. It doesn't appear that I'll be able to do that given the situation. I am having a set shipped to me by another HAMBer. I'll post my final results once I have things reassembled and running. Thanks for your help!
Once you get the replacement hub installed; check both the register and the flange with your dial indicator to see if there is a problem.
Pop the studs out and have your local machine shop give the face a thin cut to true them up. They can do it on a brake lathe and shouldn’t cost too much. Then it should have zero runout
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