My differential has been leaking for a long time and I didn't know it. Now it's making a moaning or whining sound when I'm going down the road. It's worse when it's in gear and coasting, slowing down. When under power and pulling, the noise isn't as bad. Lately it has started leaking worse from around the shaft, and I'm getting a bad shuddering when coasting and slowing down...not as much vibration when pulling, but still noisy. I was told a while back that my ring and pinion was probably worn and that's causing the noise. Now thsat it's gotten worse and is vibrating, I know I don't have much longer. I'm looking for a used rear end to replace the whole thing, axles an all, but not sure what size I have or how to tell what other ones will work with it.