[hemi43]

And one more thing I've learned over the years is do not use synthetic gear lube because you will never get rid of the chatter regardless of how many bottles of additive you put in. On my Blazer I tried using Amsoil's synthetic gear lube because they claimed it was compatible. Well, they were wrong because it sounded like the rear diff was going to break in two. I gave it a few weeks hoping the noise would go away, but it never did. I drained it and put in standard gear lube and a couple bottles of GM limited slip additive, and the problem went away. That was an expensive mistake because Amsoil products aren't cheap.