Street or Track 12″ Rear Disc Install

With the rear housing hung, its time to finish the rest of the things that get the car back on the ground. This means installing the gear carrier, axles, and brakes. I did this a couple times, and asked Shaun some questions along the way. I am much more comfortable with this setup now, but I still have a few things to figure out with the plumbing before it’s done. I am pushing that off until I take the rear off to paint the body.

This is where I started with this half of the project. Rear is hanging on its own and everything is on the lift. This is an earlier picture before I moved the front links to the bottom hole. Eventually, I am sure I need to move them again. Shaun said they should be roughly horizontal once I get the ride height I want. Good to know for after-paint install.

For this kit, I felt the directions were not as clear, or descriptive as I would have preferred. After doing the front, I was expecting a little more direction and explanation. The direction is there, but some of the details are missing, leaving the reader to second guess.

For example, the parking brake drum backing plate. The directions say to install it like the exploded diagram shows, and that’s it. The instructions mention that the kit will work with a variety of cars, so there is an expectation of some possible modification required for each situation. Looking at the diagram, the brake cable tab is up, but on the car, the tab on the frame that the cable needs to go through is low. The angle to run the cable looks odd if the drum has the tab up high, where as if it tab is low, it goes directly into the frame tab.

Asking Shaun about how it’s oriented, he said either will work, but high is suggested because it provides more clearance for the cable to avoid the suspension during travel. Makes sense, and test fitting both ways makes it clear that a high tab is better, even though the cable snakes around a little more.

Here, I mocked up the backing plate with parking brake shoes to show how things look. The axle will go over this, with a retaining flange holding everything in place, also obscuring everything from view. In this picture, you can also see I seated the new seals first. There is probably a better tool, but lacking that, I tapped it in with a punch and small hammer, slowly moving it in until it is fully seated.

Pro tip: when you have 2 axles of different length, install the longer one first. I started with the shorter one, and looked at the offset of the carrier housing, assuming since it was to the right, the smaller goes on the right. Nope, smaller is left, longer is right. Not sure if that is universal, but its true for this 9″. Trying to install the long axle in the short side quickly identifies your mistake. Time saved.

New axle in place. Turn the axle either way to line up the hole with the 4 bolts. The retaining plate goes on the outside of the bearing to hold it in place while also holding the backing plate. This is slightly different than the stock style since there are no “T” bolts coming in from the back, and rather than nuts on the outside, it has bolts that go in from the outside to the threaded holes on the housing. This is a better design, in my opinion. No spinning the “T” bolts when the thin retaining plate starts to crush.

The Dutchman axles came with their own retaining bracket, as did the SoT kit. The kit mentions facing the lip to the bearing, inward, which sounds like a better plan to keep things locked down, so I used theirs. These go behind the axle face, over the bearing face.

On first fitting, I had a difficult time getting the rotors seated enough to get the calipers installed. What I figured out was that the Dutchman axle outer diameter for the center ring was extremely close tolerance to the inner diameter for the rotor. The powder coating is thick, and causing issues with the tolerance. I ended up using the die grinder again to remove the powder coating on the inner surface of the rotor, making it seat much easier.

The directions mention using a lug nut to snug the rotor in place. For this close tolerance, I needed to put a little torque on the lug nuts to get it fully seated. I also am glad that I had some original pass through lug nuts sitting around. The acorn style I have for the new wheels wouldn’t have done the job. These axle bolts are pretty long. They just barely fit under the fancy lug nuts as well, but they did fit.

Next, I loosely fit the parking brake cable to test the route. When I do the final install, I am going to have to get something to protect the outer casing at the frame connection. I am pretty sure that is where the casing connects on the original lines, like what is mounted on the backing plate now. I could see with a few miles of wheel travel, that bracket is going to cut through the sheathing if I don’t insulate it. On the up side, the higher mounting point clears the suspension travel just fine.

With the parking brake cables sufficiently addressed for now, I moved on to mounting the calipers. The pads came pre-loaded, but they are thick, and the rotor is too, so there is very little clearance. I had to compress the pistons a bit more to get them around the rotors. Additionally, I had an issue on one side, again with powder coating thickness. I had to clear off the face of the rotor to bracket mounting point in order to even get it to align. Fortunately, once it was in place, it didn’t need any shimming to be centered.

The only place I ended up using a shim was on the outside of the caliper bolts. While I think I was fine without it, I wanted to get it closer to flush on the rotor side. Here, you can see the nose of the bolt just barely protrudes from the bracket. Without a shim, it had a couple threads exposed and was that shim length closer to the rotor.

Calipers mounted. Easier the second or third time. The last part is going to be figuring out the line routing. Additionally, there is no center connecting line on the center housing, so I need to fabricate that at some point too. But for now, I have something to attach wheels to so I can free up the lift for a little work I need to do on the convertible before the sun starts showing up on a regular bassis.

At first, I didn’t understand how the flex lines would connect and route without hitting things. I sent Shaun a note and he pointed out something I missed. Somehow, I didn’t see the port in the inside of the caliper where the flex hose connects. After hearing that, everything made sense. I connected the fitting to the caliper and attached the hoses. I am not sure the passenger side is ideally routed, but for now, its fine. I still have to revisit the center brake line once the rear is out of the car, and I can look into routing that better at that point.

With the lines in place, I bolted in the distribution block. I also connected the passenger side to the housing with the provided clip. Other than the center section, I think the lines are done.

Wheels installed and its ready to be back on the ground. That is a lot of work to see rotors and calipers through the back wheels, rather than old drums. I am hoping I also get better stopping power, not just pretty.

I am getting close to being happy with all the modifications and test fitting. I see I don’t have any parking brake brackets on the bottom of the new floor, so those will need to be welded in before paint too. There is also a missing bracket for the flex line to the floor. I should get those mocked up soon, before I forget. I am also putting off the front section of the brake cables since I don’t have those brackets yet. These SoT brakes have a bit more modification to complete the front connection as well. But for this project, I’m calling it a wrap.

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