So what are my options here, 9" tracloc clutch wear?

[SSLance]

That is a very generous offer Tim, I really appreciate that. I have never heard of the Wavetrac before, so I did a little bit of reading up on it and it sounds interesting. If things turn South with this current diff, I just may take you up on that.

I think things are getting better here the more I drive it. I've talked with a few Ford friends and several of them have told me it can take up to 200 miles or so before the chattering stops, especially if the tracloc is set up pretty tight as this one is supposed to be. I've got about 85 miles or so on it now. I'm supposed to bed the brake pads in at 150 miles...so sometime on Saturday I'm going to go for a pretty spirited drive to shake things completely out.

I sure didn't mean to start a synthetic vs dino oil argument here as that seems to be hashed out already ad nauseum. It is interesting to me though that there is still that much disagreement over the issue even after all of these years. Seems to me that once one finally hits on something that works for them, they believe in it and use it there after and there is nothing wrong with that. Hopefully the use of friction modifier in clutch type diffs is a bit clearer now though.