1947 Brake drums
 

Good afternoon,
i have a 1947 ford 1/2 ton pickup that i need a new brake drum for.
it has the square back spindles and the hubs are on the inside of the drum with a 3.25" hole. All seems normal and stock
But the bolt pattern is 5 x 4.5 instead of 5 x 5.5 that most places sell.
Any idea on what drum i need?
Thank you.

Re: 1947 Brake drums
 

Look carefully at your drum, I bet someone redrilled the bolt pattern.

Charlie Stephens

Re: 1947 Brake drums
 

Thank you. That is exactly what has been done. I didn’t recognize it for what it is.
The original lug bolts are cut off flush with the outside of the drum and new holes drilled and lug bolts installed. If I want to save the hubs and re-stud on the original bolt pattern, do you have any advice? Both front drums are this way. One drum needs replaced, the other is good. Thank you

Re: 1947 Brake drums
 

What bolt pattern do you have on the rear?

Re: 1947 Brake drums
 

5 x 5.5. I swapped out the fairly worn rear diff for a ford 9”.

Re: 1947 Brake drums
 

The brake drums should be machine within .010 of each other, on the same axle to prevent the car from pulling to one side or the other. It's not that important on the rear axles and especially if the car has front disc brakes, but with drums all the way around it's important for stopping straight that the drums be within .010 of each other on the same axle.

I was a fleet mechanic for 30-years and I never had a problem replacing the rear shoes on vehicles with disc brakes. I didn't worry about the drum sizes being the same all though technically you were supposed to.

Re: 1947 Brake drums
 

You might be better off selling (or swapping) those to someone that wants that pattern and finding some used ones at a swap meet, or buying new ones. Are the drums the same as passenger car?

Charlie Stephens

Re: 1947 Brake drums
 

I believe the drums are the same size as passenger cars from the same year.
One drum measures 12.25" ID which I believe is beyond use. The other measures 12", which I think is nearly new spec.
I had hoped to re-use the hubs and buy one new drum. It sounds like I may have to bite the bullet and buy all new.
There is a swap meet coming up in February near St Louis(Belleville IL)
Maybe I will check there before buying new.

Re: 1947 Brake drums
 

https://www.jalopyjournal.com/forum/...-hubs.1128114/

Read this thread to see what I did to put new studs in my 40 hubs (which is what you have if the hubs are inside the drums). Then you should buy a new drum from Boling Brothers which will slide right on the hub and work perfectly.

Re: 1947 Brake drums
 

With the studs cut flush, the swedged shank is still there. I would either grind the outside almost all the way to the hub before knocking them out or cut the heads off on the inside and knock the out that side.

The idea is to not damage the hub by pressing the swedged portion thru the hole in the hub.

As mentioned go for Boling Bros drums; they are good quality.

Re: 1947 Brake drums
 

Thank you!!!
I believe I have a plan for how to do this.
Thank you for the help.