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1987 Ford Bronco, beefed up 351w, JBG HD rear springs, JBG 4” coil, 10.25 rear posi, Dana 44 posi
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Discussion Starter · #1 · (Edited)
My bronco is so close to driving after my rear 1 ton swap. It’s a 10.25 sterling and I’m having a problem with the drums. They seem to have a hard time fitting and when I tighten the wheels they rub at what I think is the backing plate. Today or tomorrow I might try them with the old drum that came on it to see if it makes a difference. I don’t think the shoes and all that are set up wrong. And if they were I wouldn’t think it would only happen when I tighten the wheel and the drum is pushed. Thanks for the help.
172058

I think it’s that lip and the backing plate colliding.
 

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ate lug
88 + 96 broncos, 96 F250
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Did you get the right drums? The brakes come in two options: 2½" shoes and 3" shoes, and the drums are not interchangeable between the two.
 

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1987 Ford Bronco, beefed up 351w, JBG HD rear springs, JBG 4” coil, 10.25 rear posi, Dana 44 posi
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Discussion Starter · #3 ·
Yeah everything I bought was for 12”x3” brakes. Wheel cylinder, shoes, drums, and brake hardware. Is there a different backing plate for different sized brakes?
 

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85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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That drum isnt fully seated is it??

Here is my old write up on the sterling. Might help

Sterling 10.25 rebuild
 
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1987 Ford Bronco, beefed up 351w, JBG HD rear springs, JBG 4” coil, 10.25 rear posi, Dana 44 posi
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Discussion Starter · #6 ·
Fordbronco1995: it is a full floater.
Big Blue: no it is not, but when I do tighten them fully it gets tight against the backing plate I think. Your guide was a huge help for me when I was rebuilding mine. I must have read it 5 or 6 times to make sure I was doing it right.
 

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MidlifeCrisisUndrWay
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My bronco is so close to driving after my rear 1 ton swap. It’s a 10.25 sterling and I’m having a problem with the drums. They seem to have a hard time fitting and when I tighten the wheels they rub at what I think is the backing plate. Today or tomorrow I might try them with the old drum that came on it to see if it makes a difference. I don’t think the shoes and all that are set up wrong. And if they were I wouldn’t think it would only happen when I tighten the wheel and the drum is pushed. Thanks for the help. View attachment 172058
I think it’s that lip and the backing plate colliding.
My '87 Sterling 10.25 DUALLY has 3" wide brake shoes.

Said brake shoes is the dimension/width of the OUTSIDE of your drum brake surface area.


For reference; those lug studs are 3+" long.


You might want to double-check/confirm whether your axle uses 2.5" vs 3" brake shoes.

EDIT:
Rockauto is showing 3" and 3.5" wide brake shoes.

I definitely have 3.5" shoes.

DUMB QUESTION:
Is it possible you installed 3.5" shoes?
 

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1987 Ford Bronco, beefed up 351w, JBG HD rear springs, JBG 4” coil, 10.25 rear posi, Dana 44 posi
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Discussion Starter · #8 ·
My '87 Sterling 10.25 DUALLY has 3" wide brake shoes.

Said brake shoes is the dimension/width of the OUTSIDE of your drum brake surface area.


For reference; those lug studs are 3+" long.


You might want to double-check/confirm whether your axle uses 2.5" vs 3" brake shoes.
I bought all new 3” stuff and what was on it was 3” as well. I switched the drum that was on the problem side and moved it to the fine side and it worked fine. I also got the old drum and put it on the problem side and it fit fine. So it it just the driver side that has a problem. The passenger side works fine and does not grab anything. Could it be the hub or something like that causing it to go on unevenly.
 
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Discussion Starter · #9 ·
I’m just going to use one of the drums that came on it. It’s a factory Ford drum so I’m not sure if they had ever been changed. Are there any chain stores to get a drum turned or would it be better to go to a machine shop?
 

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I’m just going to use one of the drums that came on it. It’s a factory Ford drum so I’m not sure if they had ever been changed. Are there any chain stores to get a drum turned or would it be better to go to a machine shop?
oreillys usually does although unless they have a good rep id trust a machine shop more
 

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Discussion Starter · #11 ·
Ok, how do I check to see if they are in speck. I know the max number on the drums is the spec but not sure how to check it. Sucks if it’s past that because it’s $80 for a new motorcraft drum
 

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Thickness is checked with a micrometer, caliper, etc. Outside to inside surface thickness must remain in spec.

I bet you got a wrong drum. How does it compare with the known good one?
 

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Discussion Starter · #13 ·
Thickness is checked with a micrometer, caliper, etc. Outside to inside surface thickness must remain in spec.

I bet you got a wrong drum. How does it compare with the known good one?
The only difference my dad and I could tell was that the flange that goes to the backing plate was different.
172130

this is the hub I got.
 

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If it compares different than the other side that fits, they gave you a wrong drum in the right box...
 

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Discussion Starter · #15 ·
If it compares different than the other side that fits, they gave you a wrong drum in the right box...
It’s not the drum it’s that side of the axle. I swapped the drum that was on that side to the other side and it worked fine and the one that was working fine did not work. But the FoMoCo was working.
 

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Oh both drums work on the other side but neither on the problem side? Except the old one?

Can you get the problem side on all the way, but its tight and makes a scraping noise?

That could be just a touch of extra metal on the new drum that will wear away or the shoes are adjusted out too far.
 

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Discussion Starter · #17 ·
Oh both drums work on the other side but neither on the problem side? Except the old one?

Can you get the problem side on all the way, but its tight and makes a scraping noise?

That could be just a touch of extra metal on the new drum that will wear away or the shoes are adjusted out too far.
Yeah I can get the problem side on all the way with the lug nuts but then I can barley move it with the tires on. And the shoes are adjusted all the way in. It’s very hard to move.
 

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Yeah I can get the problem side on all the way with the lug nuts but then I can barley move it with the tires on. And the shoes are adjusted all the way in. It’s very hard to move.
take a colored grease pencil and put a line all the way around on the drum flange, install the drum and tighten, then remove the drum and check for markings on the backing plate indicating contact.
 

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Discussion Starter · #19 ·
take a colored grease pencil and put a line all the way around on the drum flange, install the drum and tighten, then remove the drum and check for markings on the backing plate indicating contact.
Yeah I was using gear marking compound but never tightened it with the lug nuts. Wanted to see how it felt with the new axle and driveshaft. I’ll try with gear marking compound when I get off work.
 
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MidlifeCrisisUndrWay
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Nothing to add but a side note:
This is exactly what causes a lot of people like you and me who own/run rear drums; the PITA of dialing in drum brakes. :LOL:😐😭
 
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