10'' Drum front and rear question

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68er

68er

68Dart GT
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Sarnia Ontario
I have read through the forum looking for answers and found lots of ways 68 darts came with drums on front and rear.

My dart has 10" front and rear drums.
The front is using 10" x 2.25 shoes
The rear is using 10" x 2.25 shoes

I found lots of front 10" x 2.25 shoes however only 10" x 1.75 rear shoes.

Can I purchase 2 sets of front 10" x 2.25 and use them on the rear as well.

I can only suspect the past owner did this as I cannot find 10x 2.25 rear shoes

I have 14" rally wheels front and rear.

Any input is appreciated

Thank you in advance
 
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63-72 Darts small bolt pattern used 10"x1-3/4" shoes, 73-76 used 2-1/2" shoes, so your Dart should have a 7-1/4" or 8-3/4" rear end or it has been changed to a later 8-1/4" or changed to big bolt pattern axles and brakes...
 
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Rear is 8.3/4
Both front and rear shoes are currently 10x2.25 in 10.060 drums.

My question is can I use front shoes 10x2.25 on rear? Since I cannot find rear shoes in 10x2.25 only 10x1.3/4
I'm assuming was what the previous owner did
 
I'd say you have the wrong shoes on the rear if it's a stock 8 3/4 A-body rear end. Any photos of the setup with the drum off?
 
Here is the photo of the rear shoes. and drum

IMG_20201126_160707.jpg


IMG_20201126_160741.jpg
 
Is your car still the small wheel bolt pattern? I don't know of any Mopar with 10 X 2 1/4" rear brakes, so, they also didn't have backing plates for that width shoe. I suspect it's supposed to have 2 1/2" wide shoes if your backing plates are off some other Mopar....like a later A-body, or B-body, or E-body. Are your shoes worn uneven from side to side? If 2 1/4 shoes are on a 2 1/2 backing plate, the shoes will be slightly cocked and will wear more on the outer edge than the inner.
 
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The wear pattern is even side to side.

14" small bolt pattern

This is why I suspected they are front shoes.

My other dart is normal 1 3/4 width

Edit

I did find some 2 1/2 width on the 4.5 bolt pattern your right
 
68er said:
The wear pattern is even side to side.

14" small bolt pattern

This is why I suspected they are front shoes.

My other dart is normal 1 3/4 width

Edit

I did find some 2 1/2 width on the 4.5 bolt pattern your right
Click to expand...
That still doesn't explain which backing plates are being used. I guess if they're working properly, just get another set.
 
I will investigate the backing plate. Thanks for entertaining me with some knowledge.
 
Are your rear drums 2.5" W friction surface? Seems they must be to match the shoes. The axle position in the photo looks correct for the 2.5" shoes, so if the rear drum was 1.75" W I expect it wouldn't reach the backing plate. There were some rear drums with a bell shape, meaning the friction surface was not as wide as the drum width, so perhaps your car originally had such drums with thinner 1.75" shoes. If so, a problem in changing to wider shoes is that your rear end could lock-up before the front, which you don't want in an accident. Try skidding in a wet parking lot to see. If a problem, you might install an adjustable proportioning valve in the tubing to the rears, or perhaps smaller diameter wheel cylinders in the rear.
 
BillGrissom said:
Are your rear drums 2.5" W friction surface? Seems they must be to match the shoes. The axle position in the photo looks correct for the 2.5" shoes, so if the rear drum was 1.75" W I expect it wouldn't reach the backing plate. There were some rear drums with a bell shape, meaning the friction surface was not as wide as the drum width, so perhaps your car originally had such drums with thinner 1.75" shoes. If so, a problem in changing to wider shoes is that your rear end could lock-up before the front, which you don't want in an accident. Try skidding in a wet parking lot to see. If a problem, you might install an adjustable proportioning valve in the tubing to the rears, or perhaps smaller diameter wheel cylinders in the rear.
Click to expand...


I found that the rear shoes are actually 2.5" wide not 2.25

The shoe actually goes right to the edge of the drum. See attached photo.

I added two new photo's

Keeping in mind this is an 83/4 diff and small bolt pattern

I found a place that offers the shoes 10 x 2.5 however I'm concerned I should be using the 10 x 1 3/4.

They mentioned the following to me

Code: 
That does not look correct possibly has 1 3/4 brake drums on 2' brake shoes? or the wrong brake offset 10 X 2 1/2 brakes take different brake offset. A-body came with a 2.3 center pilot and 7/16 studs the brake space or standoff is 2.000 on small bolt pattern and 2.800 large pattern

I added
IMG_20201127_152903.jpg
IMG_20201127_152823.jpg
 
Sure looks like you have a mismatch there somewhere. I don't know of any SBP drums that are wide enough to go on 2 1/2" brake shoes. If the shoes you have on there now are sitting square with the backing plates, that indicates to me that someone put those on the housing instead of the correct ones for the 1 3/4" shoes. With using the 1 3/4 drums on that combination, they shouldn't cover the shoes all the way across and would leave a groove and unused portion of the shoe exposed. Looking at the condition of your drum, those brakes have gotten really hot sometime in it's life. I see lots of hot spots where the drum has turned purple. Back when I was turning those, I would refuse to do it on your drum. They just ruin the cutting bits on the brake lathe. I'd recommend new drums.
 
I don't have too much experience with breaks so this is why I have my questions
I just found my rear drums off an old Dart small bolt pattern the smaller rear end however it is 10 x1 3/4 drum

I think I'm going to just order the 10 x 2.5 shoes
cudamark said:
Sure looks like you have a mismatch there somewhere. I don't know of any SBP drums that are wide enough to go on 2 1/2" brake shoes. If the shoes you have on there now are sitting square with the backing plates, that indicates to me that someone put those on the housing instead of the correct ones for the 1 3/4" shoes. With using the 1 3/4 drums on that combination, they shouldn't cover the shoes all the way across and would leave a groove and unused portion of the shoe exposed. Looking at the condition of your drum, those brakes have gotten really hot sometime in it's life. I see lots of hot spots where the drum has turned purple. Back when I was turning those, I would refuse to do it on your drum. They just ruin the cutting bits on the brake lathe. I'd recommend new drums.
Click to expand...

Are saying I buy new stock drums and go back to the proper drum 10 x 1 3/4

Then I can just order the proper shoes and all will be good. ?
 
You're sure that's a small bolt pattern eh? I'd feel better about it if you could post a photo of the measurement. Measure from the center of one hole (or stud) to the outside edge of an opposite one.
 
68er said:
I don't have too much experience with breaks so this is why I have my questions
I just found my rear drums off an old Dart small bolt pattern the smaller rear end however it is 10 x1 3/4 drum

I think I'm going to just order the 10 x 2.5 shoes


Are saying I buy new stock drums and go back to the proper drum 10 x 1 3/4

Then I can just order the proper shoes and all will be good. ?
Click to expand...
No, the shoes have to match the drum, which has to match the backing plate. If you indeed have a small bolt pattern axle, it should have backing plates for the 1 3/4" shoes. If your shoes are fitting square with the backing plates, they're not 1 3/4 backing plates, they're 2 1/2" backing plates. Putting 1 3/4" shoes on 2 1/2" backing plates will result in shoes cocked at an angle where (initially) they'll only contact the drum on the outer edge of the shoe.
 
If you have another A-body with stock 10" rear brakes, get them side by side and look for what is different. Use a tape measure and check everything, including the offset of the backing plates, and how far out the axle flange is from the backing plate.
 
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