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69 F100 4x4, I’ll attach pics of the rear diff/axles. I think I have a 9” in the rear, and I also know there are different styles: big rear & torino. I have NO idea what type I have, and I’m looking to replace the backing plate for the drum brakes since they’re scored pretty deep. Any ideas?
I don't think there is an easy way to know the different types until you tear into it. That is what my brother had to do with his 72 EB. Maybe Paul, our resident Bronco guy, has a better idea.
69 F100 4x4, I’ll attach pics of the rear diff/axles. I think I have a 9” in the rear, and I also know there are different styles: big rear & torino. I have NO idea what type I have, and I’m looking to replace the backing plate for the drum brakes since they’re scored pretty deep. Any ideas?
You think you may have a 9" (looks like one to me), but you aren't sure? Simplest way to tell visually is this: Can you put a deep socket, or a socket extension on the bottom two nuts, or would you have to use a combination wrench to get them off?
On a 9" you can't get those bottom two nuts with a socket and/or straight extensions.
As for the other options, need to take it apart to get more info/answers.
You think you may have a 9" (looks like one to me), but you aren't sure? Simplest way to tell visually is this: Can you put a deep socket, or a socket extension on the bottom two nuts, or would you have to use a combination wrench to get them off?
On a 9" you can't get those bottom two nuts with a socket and/or straight extensions.
As for the other options, need to take it apart to get more info/answers.
Jim what 2 bolts are you talking about the pinion carrier or the axle flange?
I have never heard of this and why I ask.
What I think they are talking about is large or small axle bearings and why the need to know when replacing the backing plate.
What I would do is clean up where the shoes hit and run a bead of weld and smooth it out with a grinder, little paint and call it done.
Hecck if you got the welder you dont even need to pull the axle apart to weld it up and grind.
Dave ----
That's a 9", and from the tag it appears to be original to the truck. If you need a backing plate, as long as the one you get is for a 69 truck 9", you'll be fine. As noted above, the difference is in the axle bearing size. Brake shoe size will also make a difference which is another reason why you want one for a 69 truck. I'd like to see pictures of the damage and scoring you're talking about. Like Dave said, they're usually pretty easy to fix, and may be easier to fix than find a replacement. It's not like you can go to your local yard and find dozens of them anymore.
Jim what 2 bolts are you talking about the pinion carrier or the axle flange?
I have never heard of this and why I ask.
What I think they are talking about is large or small axle bearings and why the need to know when replacing the backing plate.
What I would do is clean up where the shoes hit and run a bead of weld and smooth it out with a grinder, little paint and call it done.
Hecck if you got the welder you dont even need to pull the axle apart to weld it up and grind.
Dave ----
I was addressing the pinion carrier nuts only, as the OP seemed (to me) to be asking if he had a 9".
Back in the Day this was my "quick and dirty" method to spot a 9" versus, say an 8", at the junkyard.
That's a 9", and from the tag it appears to be original to the truck. If you need a backing plate, as long as the one you get is for a 69 truck 9", you'll be fine. As noted above, the difference is in the axle bearing size. Brake shoe size will also make a difference which is another reason why you want one for a 69 truck. I'd like to see pictures of the damage and scoring you're talking about. Like Dave said, they're usually pretty easy to fix, and may be easier to fix than find a replacement. It's not like you can go to your local yard and find dozens of them anymore.
I don’t have a welder, but did use JB Weld Metal putty and smoothing it with a grinder haha so yeah, I’m thinkin I might need to replace the backing plate
Doc Nash You said that you don't have a welder. Now might be the time to get one. IMO I would get either a Miller Autoset or a Lincoln maybe a Hobart. Why I would put the Miller above the other's is for the Auto set feature. You tell the machine what the thickness of the metal is and it will automatically set the wire speed and heat settings for you. I would go to your local welding supply and ask them where you can go to learn how. Usually a junior college will have some type of class. And since you have a son now's a good time to teach him. My late Dad taught me how to weld when I was about 6 or 7 years old. And now I'm 66 and still welding. Dad was a Proud 60 year member of the Pile Driver's Union Local 2375 in Wilmington, CA. I 'm a second generation Pile Driver. Dad and I worked all over the L.A./ Long Beach Harbor. We also did some work on Catalina Island.
Last edited by lilorbie; Mar 15, 2025 at 11:06 AM.
Reason: added to it.
You want a smooth surface that the edge of the shoes will rub against as they operate during braking and not hang up on a rough spot. I don't know how well the JB Weld will hold up under that usage. That surface originally was all steel and lightly lubricated with a brake grease to facilitate smooth actuation.
You want a smooth surface that the edge of the shoes will rub against as they operate during braking and not hang up on a rough spot. I don't know how well the JB Weld will hold up under that usage. That surface originally was all steel and lightly lubricated with a brake grease to facilitate smooth actuation.
it’s not regular JB Weld, its the SteelStik putty. Feels pretty smooth after hitting it with the grinder.
