Dwight, if you are in or near a major city there is most likely a commercial brake and clutch facility somewhere. Remove the brake caliper and pads with all associated parts, then remove the axle and then the hat, that would be the hub and rotor assembly. Remove the rotor from the hub. Take the disc pads and rotor to the brake facility and they should be able to identify the parts and replace them or even turn the rotor. You might want to replace the 2 caliper pins. Take this back and install using the other side as a guide or reference unless you took pictures to refer back to. Be sure to torque bolts and the hub to specs. It should be a Meritor rear axle. Adjust and lube the brake adjusters per specs and the correct lubricant. Most likely clay based grease. Marty