The car is a stock 57 Ford Custom. Wheels are stock 14" steel. I replaced wheel cylinders and shoes on all four corners. Front drums were good to reuse. The rear drums were both shot. I had two new aftermarket replacement rear drums so I installed them. I noticed that they're all cast iron (one piece) and the wall thickness is quite a bit thicker than the original Ford drums (pressed steel backing with cast iron rings). The problem is that now the studs don't stick out enough to barely get the wheel nuts threaded on all the way. The other concern is that the center hub is not engaged with the center opening of the wheel itself. The big question for the wheel experts is.......should the opening in the wheel be riding on the hub center? As it is, the load on the wheels is being carried by the five studs and the five lug nuts. How is this supposed to be? The new drums definitely center on the car's hubs nicely. I guess I am concerned that the wheel is supposed to do the same. However, when I fitted the wheel to the OLD drum, the center opening in the wheel didn't exactly "key" onto the hub either. Maybe this is not an issue but will the lug nuts be ok if they completely cover the stud threads when tightened to the proper torque?
Mr. VanPelt, I am not a wheel expert but it would seem best to have the drums hub centered to take the load off the studs. I had the same problem installing 91 Lincoln drums on a 71 Ford Mustang rear and ended up making some centering rings that solved the problem. If you have a lathe you can either make them out of solid bar stock or hollow pipe that has an OD just a little larger than the ID of the drum hole. Be sure to machine a slight lip on the drum side of the spacers so they don't just "fall thru" the drum. As for the studs, I guess they will have to be replaced.
It's best to have the wheel so it is centering on the hub. But in real life, old custom wheels don't work like that, and some of us have been using them for decades, without issue. The nuts are all that center the wheel, as the center hole is larger than any hub. Keep the lug nuts tight, drive it and don't worry about it. But if the nuts don't have at least 6 threads engaged on the studs, get longer studs.
Sounds like the wrong drums. They should be hubcentric. That said, I would put longer studs in if needed and run them.
The drum absolutely should be centering on the axle hub. And it sounds like you need longer studs. As to the wheels centering on the axle hubs, it's preferable if they do but plenty of aftermarket wheels don't, so I wouldn't be overly concerned. This does make having adequate stud length more critical though and make sure they're properly torqued.
My understanding of Mr. Van Pelt's post is that the drums ARE centered on the axle nub but the wheels are not. Over time many vehicles have been produced with either lug centric wheels and others with hub centric wheels. I don't think there is any real risk using a lug centric wheel mounting so long as all components (wheel lug hole cones, lug studs and nuts) are in proper condition. One might consider doing a radial run out measurement to be even more confident, or to find a problem before it becomes one. And yes, I would replace the lug studs with longer ones. Dorman products has a huge selection to choose from. That said, I have no reason to discourage hub centric wheel mounting. But with stamped steel wheels, new or old, I would still do a radial run out test. It is conceivable that lug centric would allow one to clock a wheel on the hub for minimum radial run out. Not so easy with hub centric. Ray
Put a dab of grease on the axle flange between the studs, put the drum on and pull it back off. Look inside of the drum and see if the grease transferred and got squished. I am betting the axle flange is hitting the inside of the drum and not letting it seat. Sent from my Moto G Play using The H.A.M.B. mobile app
[QUOTE="greybeard360, post: 12119685, member: 50785"Put a dab of grease on the axle flange between the studs, put the drum on and pull it back off. Look inside of the drum and see if the grease transferred and got squished. I am betting the axle flange is hitting the inside of the drum and not letting it seat. QUOTE] Really no mystery here........if you look at the pics posted by the OP, the thickness of the drum mounting face is much thicker than the original drum.....as stated by the OP......looks to be about 3x. Ray
Look at the thickness of the new drum compared to the distance that the axle hub sticks through... No comparison. The drum isn't that thick. I have run into this before. Sent from my Moto G Play using The H.A.M.B. mobile app
^^^^not wishing to be argumentative here, just trying to cover the bases.......but the nub on the axle flange is quite shallow to my eyes, shallower than the thickness of the drum web.....or so it looks to me. I have NO quarrel with your recommended test. Better to know than guess. Ray
I did that test (pics to follow).....the dabs of grease were smashed flat and very spread out. So the new drums are definitely seating well against the hub flange.
Good deal.... Get longer studs then and you are good to go! Sent from my Moto G Play using The H.A.M.B. mobile app
I force everything to be hub-centric, rotors, drums, wheels. If that means boring out center holes in drums or rotors, making spacer rings, stepped spacer rings, or turning down center registers, either straight, or stepped. My daily has stepped registers, as none of the components are "supposed" to together.
This may sound crazy, but you could weld 4 little 3/8 square pieces of steel to the axle center so that they extend out to match the dept of the drum center hole. TIG weld would be best. or, just make a round disc the needed thickness (with holes) and tack weld that to the axle center.
just thinking those are the wrong brake drums - sure think my 63 and 64 Ford's had flat drum's surface instead of that slight cone that Van Pelt has....
FOLLOW UP..........after much study and such, I felt that the ID opening of the new (thicker) rear drums was in fact correctly centered on, and riding on the hub boss. The factory boss does not protrude all that much, but it was nicely centered in the drum ID. There is a slight chamfer on the drum ID, which was needed to allow for the gentle radius of the flat part of the hub to the boss. When I finished up the brake job, and went to remount the rear wheels, I discovered that the wheel studs were not long enough to allow my lug nuts to fully engage all their threads. I researched wheel studs and found the correct thread size, diameter, and knurled diameter. Their longer length accommodated the new thicker cast drums with my stock steel wheels. Now, the lug nuts thread fully on and leave about 3/16" of thread outside of the nuts. The brakes are bled......no leaks. First test drive tonight and all went well. Firm pedal, stops straight as an arrow, and nice a vibration-free ride. Big smile on my face!
Good idea. I torqued them to 50 lbs but haven't found the factory spec for them yet. Any idea what was called for?
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