Brake Drums

rafter

Member
Are the 39-42 brake drums the same as 46-48 brake drums? Can I use 46-48 drums on 39-42 backing plates, or vice-versa?
Thanks, Rafter
 
Any '37-'48 drum will work with any '37-'48 backing plate. DD

Also, any '35-'36 REAR pass. car/light comm. drums/hubs will work with '35-'48 pass./light comm. backing plates. Not sure about earlier REAR '32 to '34 drums/hubs.
 
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I have a set of 46-48 drums on my 39 pickup chassis using the 39 backing plates. I have the drums cleaned,turned & painted and mounted and the rims blasted and powder coated black. I have decided to go back to the wide five drums and rims now.
 
I have a set of 46-48 drums on my 39 pickup chassis using the 39 backing plates. I have the drums cleaned,turned & painted and mounted and the rims blasted and powder coated black. I have decided to go back to the wide five drums and rims now.

I personally like the looks of the wide fives, with or without hub caps. My traditional '35 hot rod project will be built to run 5 on 5-1/2 wires, 5 on 5-1/2 steelies, or '36-'39 wide fives. Of course the wide fives will require changing to wide five drums whenever I run those.
 
Hey Seth,
Why do you want to go back to the older drums? I'm kinda' confused on this whole hydrolic brake issue. Any info. would help.
Thanks, Rafter
 
Hey John,
I'm kinda' in the dark about the difference between the early and late drums and backing plates. I admit I don't know what your reference to "wide 5" means. What is ment by 5 1/2 rim, width?
Thanks, rafter
 
Hey John,
I'm kinda' in the dark about the difference between the early and late drums and backing plates. I admit I don't know what your reference to "wide 5" means. What is ment by 5 1/2 rim, width?
Thanks, rafter

The reference is to the bolt pattern for the wheels. The 1936-39 pattern was 5 studs on 10 1/4 inches and the 1940-48 was 5 studs on 5 1/2 inches. Both work it is just a matter of what you like visually on your car.

Charlie Stephens
 
Ford drums have two non interchangable styles. On had a 31"4 hole and one had a 4" hole. One fit over the hub and one fit under it. Check with a vendor to see whice you have . C & G , or Sacramento Ford etc
 
Hey Seth,
Why do you want to go back to the older drums? I'm kinda' confused on this whole hydrolic brake issue. Any info. would help.
Thanks, Rafter

Good question,
The chassis on my 39 pickup was pretty rough. The kickup area of the frame over the rear axel on the passenger side was rusted out, nearly gone and I could not pull the rear brake drums without damaging the axles. So I had to bust apart the one piece brake drums to remove them from the axle.

I had a set of 46-48 drums and an abundance of 46-48 rims. At the time I cleaned up the drums and rims (had the rims powder coated black) because they were laying there and I had them. Since all of that, I have decided to go back to the wide five brake drums because I like the looks of them. So to answer your question it is just a matter of personal preference.

If you need a set of good brake drums and wheels for 46-48 I have a set ready to mount, they just need tires! ;)

What specifically are you confused about with hydrolic brakes? In 1940 ford went to the narrow bolt pattern. Prior to they used the wide fives 36-39 I believe. Hydrolic brakes were new in 39 (for ford).
 
Seth
My drivers side rear drum on my 39 will not come off. Have tried krwilson and another puller from macs, with heat, and a BFH. No Luck. Only moved it 1/4". Drum turns so not bound up on the shoes, I don't think. How did you bust apart the drum?
 
Seth
My drivers side rear drum on my 39 will not come off. Have tried krwilson and another puller from macs, with heat, and a BFH. No Luck. Only moved it 1/4". Drum turns so not bound up on the shoes, I don't think. How did you bust apart the drum?

It is hard to tell exactly the problem from your description but I think that you may have "safety hubs" on your rear end. These were designed to keep the drum/hub on the car if the axle failed. Look at the 4 bolts that hold the backing plate to the axle housing. If there are 4 bolt heads I am wrong on my guess. If there are two bolt heads and two studs with nuts remove the nuts and the drum will come off. A later "safety clip" attaches with bolts that hold the wheel cylinder to the backing plate and extends over the lip of the drum to keep it from coming off but I think you would have seen these.

Charlie Stephens
 
If it moved only i/4 then ,with the puller on it rotate the drum while turning up the nut on the puller ,its maby catching on the shoes .Rotating it should release its grip on the shoes .I take it you have removed the nut for the last pull ??
Seth
My drivers side rear drum on my 39 will not come off. Have tried krwilson and another puller from macs, with heat, and a BFH. No Luck. Only moved it 1/4". Drum turns so not bound up on the shoes, I don't think. How did you bust apart the drum?
 
Flathead Tom: The nut is on but still another 1/4 inch to go until it is in play.

Charlie: Thanks. I hope you are right. BTW, the passenger side slid of with a couple of impact wrench charges on the krwilson bolt last night. I hope the two sides are different and there are two studs with nuts on the drivers side.
 
Flathead Tom: The nut is on but still another 1/4 inch to go until it is in play.

Charlie: Thanks. I hope you are right. BTW, the passenger side slid of with a couple of impact wrench charges on the krwilson bolt last night. I hope the two sides are different and there are two studs with nuts on the drivers side.

Exactly where is the 1/4 inch play? Is the drum firmly attached to the tapered axle and the play is moving the drum relative to the backing plate? If the nut is on how do you attach the puller?

Charlie Stephens
 
Have tried two different pullers. There is a 1/4 inch between the shoulder of the hub and the axle nut when I use the discount puller that is on Mac's.
With the discount puller, I left the axle nut on (backwards) to protect the threads and to keep the hub on the spindle when it lets go.

When using the krwilson, you are right, I don't use the hub nut but rather special nut they furnish to protect the spindle. With the krwilson nut, there is probably another 3/4 to 1 inch before the hub shoulder contacts the nut. It should be free long before that, I hope.

The hub is firmly attached to the spindle. I can tell it has released about 1/8th to 1/4 inch because the hub has pulled that far past the end of the key. It was flush when I started.

I think your safety hub suggestion is a good one.
 
Have tried two different pullers. There is a 1/4 inch between the shoulder of the hub and the axle nut when I use the discount puller that is on Mac's.
With the discount puller, I left the axle nut on (backwards) to protect the threads and to keep the hub on the spindle when it lets go.

When using the krwilson, you are right, I don't use the hub nut but rather special nut they furnish to protect the spindle. With the krwilson nut, there is probably another 3/4 to 1 inch before the hub shoulder contacts the nut. It should be free long before that, I hope.

The hub is firmly attached to the spindle. I can tell it has released about 1/8th to 1/4 inch because the hub has pulled that far past the end of the key. It was flush when I started.

I think your safety hub suggestion is a good one.

Are you sure the key didn't move? I don't think the hub will move a little but rather it will pop when it releases. Are you near anyone that can look at it?

Charlie Stephens
 
Not sure that the key didnt move a little. But certain that the hub had moved.

But I took the nuts off the studs and I was able to rock the hub just slightly. So it wasnt firmly attached. I put the krwilson on and hit it with the impact wrench for about 20 seconds and it released. I guess one of the brake shoes was causing the hub to cant slightly and freeing up those studs that hold bottom of the shoes eliminated the binding? Didnt see a rust ridge on the drum or any kind of safety item inside the hub.

Thank you, everyone, for the feedback and suggestions.
 
For what its worth, I think the krwilson pulls on the drum more parallel to the spindle axis than does the discount puller from Macs. Canting the drum even slightly seems to be a problem when pulling it off.

BTW, my problem spindle taper and inside of the hub taper have some mild corrosion, kinda like sludgy surface rust. That must have been the real problem.
 
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