Technical Thoughts on welding grooves in drums and then turning them true.

Copy pasting from another forum:

Not sure if this would be worth it on small car stuff but for bigger truck and industrial equipment it could be the right move.

 

That said, I find it VERY hard to believe that with some quality time on Rockauto you can't find a drum that will fit over that hub and have the correct ID, perhaps slotting the holes will be required but that's not a big deal.

 

Take no chances when working on someone else's brakes. No matter what your customer says, the family of the person he kills when the brakes fail is going to sue YOU!

 

Murray Park in Ohio, French Lake in Minnesota, or Desert Valley in Arizona will have cars with drums that fit your project, and likely in better condition than what you're working with. I never like to see folks resort to modifying or cobbling together fixes when replacing with good OEM parts is an option.

 

Looks like plenty of good surface area left on them for braking. As others have said clean up the surfaces and go with it. The rears do the minority of the braking with 65-70% being done with the fronts.

 

Don't worry, folks, I'm still looking for good drums. I've got a couple calls out.

 

A couple of years ago, to get a 64 Fairlane's brake issues solved I needed new front drums, when they came they didn't include the hub
I "luckily" had a hole saw of the right dimensions which I used a piece of copper pipe to keep it somewhat concentric on the stud. The new drum was the right center hole diameter so it self centered. Finding a drum that is the same dimension would be the only issue.

 

Found a set of new brake drums at the part store for a sixty six chrysler new yorker. Same size and they look like they should work from the pictures.But I won't have them till three o'clock

 

If they truly are from a '66, I’d be more than surprised if they are same as those in your OP photos, but stranger things have happened.
Fingers crossed.

 

Hey, c'mon now !
Trying to introduce common sense, responsibility and safety concepts to this group of wannabe hot rod rebel punks will only invite ridicule & get you casted as a "Karen" who doesn't understand a fncking thing about hot rods.

 

Re-sleeving commonly done in vintage sports & racing cars with aluminum brake drums.
Steel inserts also commonly used in aluminum flywheels.

 

All the Warning's in a Wilwood kit ,

 

What about brazing the grooves level and then turning the drums?

 

Update for today. I finally got the drums for the 66 new yorker and though they are deeper offset They fit onto the hub and do not hit the backing plate at all. Only problem is the inside diameter is a little larger than the stock drum, so it's not an exact tight fit. The new drum measures 2.835 and the old drum measures 2.8100. I'm gonna put it together tomorrow morning and see how it does.

 

Looks like a good ending to the story….
The customer will be happy, the safety police can sleep tonight and the Mopar guys have some new interchange information. Good job.

PS: I wouldn’t have welded them, I’m in the “true em up and run em with the grooves crowd”

 

Well, the show ain't over yet and with several hurdles seemingly still ahead, happy ending may prove elusive, but we're all rooting for it.

Yours truly,
Safety Karen

 

Thanks for the follow-up

 

Still need to check run out .

 

I’d love to hear from someone who has experienced or witnessed a drum being built back up with a process that is applicable to a cast iron drum.

I know that aluminum drums have been sleeved, why not cast iron? I am genuinely curious.

I like the idea of using a sacrificial drum to make an insert repair sleeve but then you’ve gotta have just the right pile of junk to get what is needed.

 

Another update. I don't like that The hole of the new drum doesn't fit on the hub tight. The guy that I got the front drums from that are from a 68 super bee said I could have the rears sitting on the side of his house. They fit nice and tight on the hub. But they touch the backing plate a little bit. So I think all I have to do is 3 sixteenths off the edge. And everything should work perfectly. Gonna turn them and cut the edge. And we'll report back in a little while.

 

Brian, I hope you won't mind my continued observations, but before you get too far, please check the wheel-to-drum fit, which I suspect might've also been an issue along with the hub-to-drum centering hole clearance for the new drums you got yesterday.
Also, the used drum in your latest photo appears to be turned/worn past the max ID and possibly making it/them worse choice than the OE drums with the groove.
Good luck.

 

While I don't have personal experience, I've "heard" from colleagues of some attempts of insert being machined & placed into cast iron or steel brake drums, but they were on some very obscure (read unobtainium) drums and with no feedback whether they actually worked or if they did, how long or how well.

I've also heard (from reliable sources) of new brake drums having been machined from billet steel, but I don't think either of the above approach being a viable option for the kind of drums Brian is dealing with, as I suspect good used or even new ones can probably be found/obtained relatively easily & inexpensively.

 

Thanks for the suggestion on fitting it to the wheel. Just checked and it clears everything fine. As for the thickness of the drums I measured them . Just a hair over eleven So I don't think they've ever been turned.

 

Nice old drum mic.

 

At least in your photos the drum appears to have a quite deep wear pattern where the shoes have been making contact, also evidenced by the high ridge close to the edge, not to mention fair amount of deep corrosion.
You might also consider measuring higher up, more in the center of the contact surface and perhaps use (borrow or buy ?) more accurate/precise measuring equipment.

 

You can barely feel the ridge with your fingernail on the outer edge. Once they clean.
Up. I will measure them again. Maybe you see the black marker line that I put on the drum to be cut off And Are mistaking that with the ridge?

 

I agree. I know a guy who rebuilds industrial electric motors and has a machine to build up worn shafts, which are generally steel, obviously. Couldn’t help but wonder if it could be set up for cast iron, perhaps with an [edit; suitable filler] etc.

 

Automotive manufactures have been using cast iron from the git for drums and rotors for a reason.

 

You could have the inside of the drums flame sprayed with new metal. The company worked for had lots of worn expensive parts built up with this process.

 

Everything worked out great. Everything clears and everything works. So that's 1968 super bee rear drums with the inside lip cut off quarter inch. Measured the drums after the cut and they are 11.030. Still got a bunch of life left.