Junkyard swaps: Rear brake options for 8 1/4 and 8 3/4 axles.

Brakes for your Classic Mopar

  1. Kern Dog

    Kern Dog Well-Known Member

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    Hello all,
    I have a few rear axles here that have no brakes on them. In the past, I'd just go to the nearby self serve wrecking yards and grab some 10" drum assemblies and use them. As the rear wheel drive cars are harder to find, I'm having to expand my search.
    I have seen trucks and vans with 8 1/4 and 9 1/4 axles. The 5 lug hub versions usually have 11" brakes. Thats a bit oversized for what I want but it is better than nothing. I once swapped Dakota 10" drums onto an 8 3/4 axle. I could do that again if it comes down to it.
    See, I have a 65 Valiant that will get a 3.21 geared 8 1/4" axle. It came to me without brakes. A car this light would be fine with 11" discs and 10" drums. I have a 72 Duster that is getting a 3.55 geared 8 1/4" and it needs brakes too.
    I have a fuzzy memory of people adapting Jeep rear discs to 8 1/4" axles. What does it take to make that work? Jeeps and Durangos are common in the yards. Is there a range of year models that I need to search for?
    I have a couple of 8 3/4 axles that need brakes too. One has the stock tapered bearings, the other has fixed/non adjustable type bearings. Can the Jeep/Durango discs be fitted to them?
    I'm not fixated on any specific type of brake. Drum or disc will work, I just need something that requires no trips to a machine shop and has no no crazy or unusual parking brake cable arrangements.
     
  2. Dana67Dart

    Dana67Dart Like a fine wine, only getting better with age! FABO Gold Member

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    Mopar action mag, October 2018 has part 2 of a 2007 and down Jeep liberty rear disc swap to 8 3/4 (65 to 74) 5x4.5
     
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    • Kern Dog

      Kern Dog Well-Known Member

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      I may consider that. It looks to be a bolt in for the 8 1/4" from classic cars except for the parking brake connection.
      I
       
    • mbaird

      mbaird mbaird

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      I used Jeep discs on my Fastback . It was pretty easy . Not sure why some make it sound so hard . Adapting the E-Brake cables requires some fabbing but not brain surgery.
       
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      • Kern Dog

        Kern Dog Well-Known Member

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        Jeep Liberty or another model ?
         
      • jos51700

        jos51700 Well-Known Member

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        Liberty Liberty, Lib-er-teeeee

        Screen-Shot-2019-03-14-at-3.20.22-PM_1000.png
         
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        • MoparMike1974

          MoparMike1974 FABO Gold Member FABO Gold Member

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          Anyone ever put an EMU in their duster?

          As far as the topic, I picked up some 11" backing plates from someone here and bought the rest of the parts from rock auto. Those 11" drums fill out the entire inside of the 15" cop rims.
           
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          • dodgedifferent2

            dodgedifferent2 Well-Known Member

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            I make an adapter to run mustang caliper and rotors for the 8 3/4.

            I detest the mopar drum parking brake assembly.
             
          • halifaxhops

            halifaxhops It's going to get stupid around here! FABO Gold Member

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            • jos51700

              jos51700 Well-Known Member

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              Aaaaand you forgot to post pics
               
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              • Kern Dog

                Kern Dog Well-Known Member

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                I have a mixed report.
                I went out to a couple of "Pick N Pull" yards today.
                These guys embraced an annoying business model a few years ago. They have made it more customer friendly for the people that rarely ever go to the yards BUT it slows down everything for the people that know what they are doing. The cashier offers to look up their inventory for customers, to print out a list of the cars, to quote prices too. All the while, I have already looked at their online inventory and I know where the cars are in the yard.
                I wanted to find some 10" drum brakes. Simple, effective and relatively light.
                No rear wheel drive classics at the 2 yards I went to. The first was supposed to have a '69 Fury but the car was not there. This is a common thing....their inventory is rarely ever 100% accurate.
                The 1/2 ton trucks and vans that did have rear drums were 11" and the bigger 5x5 bolt pattern that started sometime around the 1985 model year. I saw several Jeeps and a few Dakota trucks with both disc and drum brakes.
                I did find a '73 Van with an 8 3/4" axle and 11" brakes. I pulled the 3.23 3rd member and the brakes. The shoes were worn out, the van looked to have been sitting for 20 years so I suspect that the wheel cylinders were rusted solid too.
                The counter monkey did what most of them do: Itemize every individual part. Brake shoes. Springs. Wheel cylinders. Parking brake levers. Backing plates. Drums.
                I asked if they had a sales code for a "Brake assembly". He said no.
                $ 126 for the two drum assemblies with all the fees. The drums were rusty and the backing plates were heavily pitted. $126 for parts that aren't exactly what I wanted and I'd need at least another $70 or more in parts to make the brakes complete. I'd be in the set $200 easily.
                The 3rd member was $130.
                That is $250 for brakes and gears. The entire axle complete would have been right at $200 but I already have several axles here that need brakes !
                 
              • Kern Dog

                Kern Dog Well-Known Member

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                The Jeeps I saw had a variety of brakes. This one looked to be 10" drums. Jeep A 1.jpg Jeep A 2.jpg

                The drums looked normal.
                Jeep A 3.jpg

                Check out inside though....Looks like part of the anti-lock setup.
                Jeep A 4.jpg

                I would have grabbed these but one drum was missing. I was unsure if they'd fit though since it had an axle that didn't look like an 8 1/4".
                 
                Last edited: Mar 7, 2020
              • Kern Dog

                Kern Dog Well-Known Member

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                Another Jeep. This one looked like it had 9" drums.
                Jeep B 2.jpg Jeep B 1.jpg Jeep B 3.jpg
                 
              • Kern Dog

                Kern Dog Well-Known Member

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                This 1995 Jeep had what looked like 9" drums like others that I saw. I didn't have a tape measure to confirm.


                Jeep C 1.jpg Jeep C 2.jpg

                It did have an 8 1/4" axle so the backing plates are the right pattern.

                Jeep C 3.jpg
                They spray orange paint on the truck parts so they can charge more for them.
                 
              • Kern Dog

                Kern Dog Well-Known Member

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                Looking at the Rock Auto website, the early Cherokees did use 9" drums with a Dana 35 axle.
                 
              • Johnny Mac

                Johnny Mac www.blueprintengines.com FABO Vendor

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                Couple observations.

                In the past when i had abundant time, i would do anything to save a buck, but spending $120 on drum brakes you have to pull yourself seems pretty steep, especially rusty ones that need half the stuff replaced.

                You can piece together a disc setup via rockauto for under $200. Easy. Hell Speedway sells one for $350 complete for a 8 3/4.

                If you do want to keep drums. I have some 10 inch ones and some 11 inch ones for a 8.75.

                Also have whatever comes on a running, driving 1977 8.25. Would let them go for a song if needed. Lmk.
                 
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                • Kern Dog

                  Kern Dog Well-Known Member

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                  I actually have 4 B body 8 3/4" axles and an A body 8 1/4" that I got with no brakes on them. In short, I need to put brakes on 5 axles.
                  I have six 10" backing plates, six 10" drums and a bunch of shoes. Enough to do at least 3 axles if I can find all the guts. I do have a box of springs, adjusters and other misc hardware. It is the levers, cables and wheel cylinders that I don't have. Wheel cylinders and springs can be found locally but the parking brake parts and those horizontally positioned 1/4" thick steel bars are not that easy to find. That is why I was hoping to find some complete assemblies. I've messed with these cars for years but it can be confusing to me to look at a pile of drum brake parts and know if I have the right stuff. I used to do rear brake jobs one side at a time so I'd have the other side to look at to get it right.
                  I have a couple of drum brake cars out back that I can look at to see what parts that I need. I have found though that there were some changes over the years. For years, I was fortunate to have an easy time finding what I needed at the junkyards. I knew that this day would come but it still sucks to see the old stuff get so hard to find.
                   
                • Johnny Mac

                  Johnny Mac www.blueprintengines.com FABO Vendor

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                • MOPAROFFICIAL

                  MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                  Theres some 10 x 2+" off a 8 3/4 from an a 108 van near me.
                   
                • Kern Dog

                  Kern Dog Well-Known Member

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                • Kern Dog

                  Kern Dog Well-Known Member

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                  Is it fair to believe that if an 8 3/4" axle has the aftermarket NON adjustable bearings that these Jeep brakes can be used?
                  I have a B body 8 3/4" axle with "Green" bearings that has no brakes on it...
                   
                • jos51700

                  jos51700 Well-Known Member

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                  When they itemize all the crap, that's when I stop going to that yard.
                   
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                  • Kern Dog

                    Kern Dog Well-Known Member

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                    That would be a great idea BUT the "Pick-N-Pull" yards have bought out most of the independent junkyards to the point of being a monopoly around here. Sometimes I have been lucky and had a cashier that is also the Store Manager.
                     
                  • jos51700

                    jos51700 Well-Known Member

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                    That's why I stay with little guys.
                     
                  • Duster 72

                    Duster 72 Active Member

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                    Sorry to junp in here but I'm curious will the drums and backing plates off my 73 w150 with an 8 3/4 work on my b body 8 1/4? I know drums are wrong bolt pattern but they can be redrilled
                     
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