i have an 89 mustang GT Hatch 5speed that has a horrible knock in the rear end. it happens about every revolution of the tires it seems. faster and a lil more dull at speed slower and a little more harsh and singular at slower speeds. I have the car jacked up now and thought it was a bad wheel bearing. pulled It and it had some pitting on it. sanded it smooth and put it back in no change. pulled axle and left it out and no change. I currently have both axles out. have pushed and pulled on drive shaft and she is tight. there is some play in the carrier. I just changed the drivers side wheel bearing and put new fluid with the friction additive for the LSD. I have no idea what to do next.