Will Handzel
April 1, 1998

Step By Step

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If you want stopping power with style, the new Ford Motorsport disc brake kit (PN M-2300-G) bolted on to your rearend will do everything you want it to.
The kit comes complete with the backing plate/caliper mounts, rotors, calipers, and mounting hardware. The slick trick about this package is that the parking-brake mechanism is located inside the hub of the rotor. These same brakes are used on the Ford Explorer, so they are a proven package.
The rearend chosen for this article was not out of a truck or a big car, so this installation will show all the steps necessary to mount these brakes. With any rearend, the drums, axles, and backing plates will need to be removed first. Sometimes tapping on the drum with a hammer makes it easier to slide off the drums.
The stock brake lines need to be unbolted to remove the backing plates. The lines will need to be modified or replaced to fit the new disc brake calipers.
The axles slide out of the housing after removing four retainer bolts and nuts.
The correct housing end for this brake kit is the 2x3.56-inch pattern end with a 3.150-inch outside-diameter bearing, which is the one on the left. These ends are found on ’77–’86 truck rearends and ’73–’79 big cars (Currie calls them Torino housing ends). The rearend chosen had standard large-bearing housing ends, which needed to be replaced.
The axles you use in this application are important because the distance from the wheel-flange mounting surface to the start of the bearing surface is different for various axles. Ford likes this distance to be close to 2.500 inches, but Currie found that this kit will work with a 2.188-inch or greater distance to clear the parking brake mechanism and place the caliper on its mount correctly (since the caliper is floating and the rotor is located by the axle wheel flange, which locates the caliper). The axles in this housing were 2.090-inch pieces, so they were replaced with 2.226-inch Currie forged alloy axles set up for Explorer drum brakes. If you start with a 9- or 8.8-inch truck or big-car rearend, you won’t have to replace the axles because they have 2.188 inches between these two points.
The rotors come with 5x4.5-inch bolt patterns, so if you need a different one, the rotors will need to be redrilled. This application required a GM 5x4-3/4-inch bolt pattern, so the rotors and the axles were redrilled. Currie charges $20 to redrill rotors.
The one trick to installing this kit is a 0.200-inch spacer that Currie can provide and Ford plans to carry. The spacer is needed because the backing plate is thicker on the disc brake setup than on the drum brakes. To get the axle retaining plate to clamp down tightly on the bearing in the housing, the spacer needs to be used. Ford plans to offer various spacers for different applications.
With the 2x3.56-inch housing ends, the disc-brake backing plates/caliper mounts slide right on.
The Currie axles had new bearings and seals pressed on after the 0.200-inch spacer was in place (arrow). Installed, the new bearings cost $27.99, and the seals cost $5.99 from Currie. New bearings and seals are good insurance against an axle failure on the road.
Getting the spacer seated in the housing and fitting the four bolts into the holes for the axle retainer plate is a little tricky. Currie achieved this feat with two hands, a screwdriver, and some patience. Having an axle with an access hole in the flange definitely makes this job easier.
The rotor then slides over the axle flange and the caliper is bolted on. The floating caliper is held on the backing plate with two bolts, so it is easy to install. The brake line and parking-brake cable will need to be custom-made for your application, but the components in the kit are O.E.M. quality, so hooking up these systems should not be too complex.

Disc brakes on the rear axle of a car are impressive for many reasons, but usually their cost keeps the majority of enthusiasts in drum brakes. Recently, Ford Motorsport Performance Parts made a new kit available, reasonably priced, that comes with everything you need to bolt disc brakes on a Ford 9-inch or 8.8-inch big-car or truck rearend (or any rearend with the correct housing ends on it). Although the kit is very straightforward to install—as you will see when Ford-rearend specialist Currie Enterprises in Anaheim, California, installs a kit on a 9-inch—many tips and tricks shown here will make the job easier when you decide to install this kit on your own.

What Is Needed?

The five-lug brake kit uses an 11-inch solid rear rotor clamped by a single-piston floating caliper. The parking brake mechanism uses the hub of the rotor as a brake drum, so it is hidden under the rotor. This design looks clean from the outside but still offers the safety of a parking brake system. The kit is actually the rear brake setup straight off the Ford Explorer 8.8-inch rearend, so the components are proven on the street—in case you doubted that a solid rotor could handle the punishment.

The keys to bolting on this kit are the housing ends and the axles on the rearend. This kit is designed to bolt on to a truck or big-car housing end because the backing plate/caliper mount for the disc brake kit has a 2x3.56-inch bolt pattern, which corresponds to the 9- and 8.8-inch truck and big-car housing ends. Also, the axles need to be a minimum length from the bearing surface to the wheel flange to provide enough clearance for the parking-brake mechanism. There are plenty of Ford rearends that meet these requirements, and if you don’t start with one of these, Currie can modify your existing rearend to work with this kit.

According to Currie, this kit will be a direct bolt-on to rearends from ’73–’79 big passenger cars and ’77–’86 pickup trucks. An easy way to identify the ends is to look for 3/8-inch bolts on the housing ends versus the ½-inch bolts used on the other rearends. Currie calls all of these “Torino” housings. If you don’t know if you have one of these rearends, check out the photos of the housing ends needed and the dimensions of the axles. With this infomation, you can decide what you’ll need to do the job.

Installing the Kit

In our example, the rearend did not have the correct housing ends, and the axles were too narrow to clear the parking-brake assembly. This was good and bad, because it made us go through every step necessary to bolt on this kit, but it also added cost in parts and labor. A lot was learned from this situation, which is included in the story, so we are hopefulthat it will make your life easier when you decide to install this kit.

This Ford 9-inch rearend was from a ’57–’72 Ford car. It has big-bearing ends with ½-inch holes. The rearend had big drum brakes that were able to stop the car just fine, but the drum brakes didn’t look good through the aftermarket wheels, so the owner had been looking for a reasonably priced, clean rear–disc-brake kit that offered good stopping power. He felt this new kit fit the bill perfectly.

Unfortunately, this rearend needed new ends, at a cost of $49.95 (from Currie), plus $89.95 for Currie to cut off the old ones and weld on the Torino ends. This rearend also needed to be narrowed, included in the $89.95, and new spring pads needed to be welded on, which cost $26.95 to install. The stock axles were replaced with Currie forged-alloy axles. Check the photo of the axle dimensions to understand why the axles needed to be swapped. The axles cost $299.95 for the pair, cut to fit. All this expense should encourage you to find a rearend with the proper housing ends and axles. Even if you need to have the housing and the axles narrowed, it’s best to start with the right components.

All the steps to installing the brake kit are covered here. The installation of the brake lines and the parking-brake cable will be a custom application for your vehicle, so they are not shown. You could probably modify the existing brake lines to mate with the disc brake calipers, but the safest method is to bend up new lines. Making new brake lines requires a double-flaring tool, a tubing bender, and new line and fittings. The parking-brake levers and cable anchors that come out of the backing plates accept many different cables, so the factory parking-brake cable on your car (whether it is a Ford or not) may work. Also, the backing plates can be swapped to locate the parkig-brake lever either above or below the tubes on the housing to clear springs, shocks, or any other interference problems.