Packard Forum Index » Post-War (1946-54)

Hi
I am trying to remove the rear brake drums, but no amount of pulling pushing and belting it with a heavy lump hammer is moving them - is there something I am NOT doing ?

Best regards Michael

There is a complete link here, that someone else will be able to find for you. Make sure you have the correct heavy duty puller. Don't want to over do things as you don't want to break the drum. If you don't have a torch, go to Home Depot and get mapp gas, a nozzle, and ignition tool. Heavy sledge hammer, good back, and PATIENCE. I usually give it a few wacks, tighten, again several times. Heat up slowly with Mapp gas, few more wacks, heat a bit more, more wacks. Do NOT need to over heat the hub to red, just getting it hot will do. Keep tension on wheel. Go watch some tv, so you can wind down and stop cussing at yourself about that stubborn wheel. Have a good nights sleep, and sometime during the night the wheel fairy stops by and there is you drum loose on the shaft. Never had one pop more that a couple of inches, but wise to put moving blankets under the wheel in case it should pop completely off the axle. Or keep the axle nut on axle. Make sure brake pads are not putting pressure on the drum. A little penetrating oil along the way will not hurt anything. On my 39, 12 had to drive ten to fifteen minutes with the axle nut just a touch loose, to break those loose.
If there is a rubber or fibre gasket under the axle nut, pry them out with jewelers screwdrivers or something similar.

There's a long string last year on this. Look back in this forum. No one had a full proof method but does require a stout puller. I think people generally over tightened these thinking the taper was holding the wheel, but the taper only aligns the wheel the key holds the wheel from turning. Good luck.

Thanks to everyone - now read the "string" from last year from Thad Gegner - so we have to find a very stout hub puller and have a lot of patience - I have had TWO "restorers" over 5 years, both assured me the brakes were in order - now knowing all the hassle of getting the drums/hubs off we are SURE they NEVER did !!!

Best regards Michael

Quote:

Jim, I believe it is the other way around: the key aligns the drum on the axle and the taper is what secures the axle and drum together. The torque for the axle nut is a huge 250 ft. lbs. The nuts must be tightened per spec or else the drum and axle will not be secured and the key will be severed.

(o{}o)

Also, no grease or oil on the axle and drum tapers. They must be squeaky clean for assembly.

A BIG, STRONG puller is the secret. Take the nut off, turn it around and screw it back on flush with the end of the axle. This protects the threads, prevents the shaft from getting mushroomed and holds the hub from flying across the shop.

I have a factory puller for Chryslers. It has a cone shape and bolts onto all 5 wheel bolts. At the end of the screw is a big dog bone, battered by years of being beaten with big hammers but it has never failed to do the business.

I'm not going to re-argue this one or succomb to mythology. I spent too many hours in graduate metallurgy and engineering classes and too many years practicing.
Go to any mechanical design source book on axles/drives and it will describe the functions of a keyway, shaft, etc.
There's also plenty of good resources on torqueing, wet vs dry (and galling). This wasn't thought of/studied much before they went to aluminum castings and studs were stripping wholesale at dry torque specs.

Your credentials are impressive. My comments were based on what I was taught and have practiced for many years. If what you say is true, then why have a tapered shaft? Why not just have a straight shaft and key? I (and probably many others here) am trying to understand why the taper and key was commonly used in the axle design in our Packards and other makes. Thanks in advance for your reply.

(o{}o)

Put it into context. There's a sometime problem releasing the drum/hub from the shaft with this design. There's likely many causes.
I do not know why Packard, et al, used this design in that era. A good research project for someone.
The tapered shaft and key is common and was in use before and still in use for some applications.

I will say in order for a taper (without a key) to transmit torque it has to be a pressed or shrunk interference fit. I don't think that's the case here. Maybe that's what they were thinking/trying to achieve, I don't know.
A key prevents two pieces from moving in relation during rotation and that's what transmits torque.
A taper provides alignment without a bearing.
So having a key and a taper transmitting torque would be unnecessary.

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Seems that the head on my drill press is just held on by a tapered shaft- no key way.