Vehicle: 1998 Jeep Cherokee Sport
Axle: Chrysler 8.25
I hate drum brakes and found there are a few different ways to change the rear brakes to disc brakes on the XJ. I found you can swap any rear discs from a 1994-1998 GRAND Cherokee with little modification.
94-98 GRAND Cherokee Rear Disc Brakes and proportioning valve
Dremel with grinding stone
Step 1:Acquire all the parts needed from a Grand Cherokee, years 1994-1998. Calipers, Backing Plate, Soft lines, all the hardware.
Step 2: Jack up your Cherokee and put it on jack stands.
Step 3:Remove Differential cover to drain the fluid. Be sure to remove only the lower bolts first to drain the fluid easier and so it doesn’t get every where. (13MM)
Step 4: Remove pinion shaft bolt (8MM). Once this is done you can push both of the axles in, causing the C-clips to fall off the axles. Then pull both axles out.
Step 5: Remove all the drum hardware from the axle. Leaving only the 4 studs for the backing plate.
Step 6: Now you will need to take the ZJ backing plate and grind down the center to fit the axle. I used my dremel with a grinding stone and it worked just fine.
-I went ahead and change the 4 studs as they were a little rusty and old. I used grade 8 3-8/16 x 1 ˝ bolts with lock washers and new nuts. Just use a hammer to pound out the old studs. I would recommend this just to make the install a little easier.
-I also went ahead and change the axle seals. Use a flat head or pry bar and pull the old seal out. And I used a rubber mallet to put the new seal in. Be sure to hit the seal in a circle so it goes in evenly.
Step 7:Install ZJ backing plate
Step 8: Install parking brake assembly. Retaining clips then bottom spring/ adjuster then E-brake cable pivot then top spring
Step 9:Install axles. Install c-clips and pinion shaft bolt. Be sure to clean the differential with brake cleaner before reinstalling.
Step 10:Install Rotors
Step 11: Install Calipers. You will have to reroute the brake hard line to fit with the soft line.
Step 12: Install brake cables. I went ahead and bought new cables from Napa. Part numbers: 95969 and 95963. You can either use the stock cables form the XJ or ZJ but modifications will be needed. I didn't get any pictures of this.
Step 13: Install Proportioning valve
Here are two excellent write ups as on how to change out the Proportioning valve. You can either change the whole unit or just the internals.
Step 14: Install differential cover. Now is the time to paint it if you like.
Step 15: Bleed brakes/ adjust brake cable.
Over all it is not a hard modification/install. Basic tools were needed. I would recommend. Less body roll when breaking and no more clunks after releasing the brakes from a stop.