Rear Brake Identification

[Austin Spencer]

So, I don't own any Mopar cars, nor have I ever worked on any, but I've got quite a problem and it pertains to some Mopar parts. I've got a 1973 AMC Javelin, and the guy I got it from put a 8 3/4" rear into it, and after a lot of brake work and guessing around, I've found out that he did some odd combination of AMC rear drum brake parts and Mopar parts. I've been trying to identify the backing plates and I know they are Mopar, but I can't distinguish if they are from an A body or B body or if they are 10" or 11". All I know is that the differential came from a 68 Roadrunner, so I can assume the brakes did as well. I'll try to post a few photos, and if anyone can point me in the right direction as to what drums, shoes, and other parts I should get I would greatly appreciate it.

 

[Alaskan_TA]

If he was right & it came from a '68 B-body & it has the original axles then the drums will have a 4.5" wheel stud pattern.

You can measure the backing plate diameter also.

 

[Austin Spencer]

Here's a few pics of the front and back. It has a code on the back of one, it looks like a 7SE?353

 

[Austin Spencer]

If he was right & it came from a '68 B-body & it has the original axles then the drums will have a 4.5" wheel stud pattern.

You can measure the backing plate diameter also.

Yes, it does have a 4.5" wheel stud pattern, should the backing plate diameter have the same diameter as the interior of the drum? if so that makes it a lot easier.

Edit: Just measured, and the backing plate's diameter is 11"

 

[72bluNblu]

Yes, it does have a 4.5" wheel stud pattern, should the backing plate diameter have the same diameter as the interior of the drum? if so that makes it a lot easier.

Edit: Just measured, and the backing plate's diameter is 11"

If the outside diameter of the backing plates is 11" it should be a for a 10" drum. If it's 5x4.5" that would be a 10x2.5" drum set up. The backing plates for 11" brakes have a 12" outside diameter.

 

[Austin Spencer]

If the outside diameter of the backing plates is 11" it should be a for a 10" drum. If it's 5x4.5" that would be a 10x2.5" drum set up. The backing plates for 11" brakes have a 12" outside diameter.

I see. Alright, well that would explain why the 11" drums and many other parts didn't work. Will my brakes have to have the exact same set up as a roadrunner? On the AMC it has a more similar set up to a Ford with the springs and the self adjusting kit, and that's how it was when I first got it.

 

[72bluNblu]

I see. Alright, well that would explain why the 11" drums and many other parts didn't work. Will my brakes have to have the exact same set up as a roadrunner? On the AMC it has a more similar set up to a Ford with the springs and the self adjusting kit, and that's how it was when I first got it.

That would be the easiest way to do it, sure. Set it up like a stock Mopar 10x2.5" brake system. I wouldn't say there’s no other way to do it, but anything else would probably mean a lot of research and/or custom work on your end. The 10x2.5" brakes were used up until the late eighties on all kinds of Mopar cars and some trucks, the parts are readily available and fairly inexpensive. You should be able to find all the parts at your local parts store, or RockAuto, Summit, etc. Just make sure they're 10x2.5" with a 5x4.5" bolt pattern and you should be good to go.

 

[Austin Spencer]

That would be the easiest way to do it, sure. Set it up like a stock Mopar 10x2.5" brake system. I wouldn't say there no other way to do it, but anything else would probably mean a lot of research and/or custom work on your end. The 10x2.5" brakes were used up until the late eighties on all kinds of Mopar cars and some trucks, the parts are readily available and fairly inexpensive. You should be able to find all the parts at your local parts store, or RockAuto, Summit, etc. Just make sure they're 10x2.5" with a 5x4.5" bolt pattern and you should be good to go.

Awesome! Thank you very much!