Thought I was �chatter free�

[Jack J.]

[Leif A.]

[Gary R.]

[Jack J.]

It depends on how the posi was rebuilt. 80w90 and 2 bottles of additive should be enough to resolve posi chatter. The parking lot figure 8 will get the oil mix into the clutches but so will driving the car. Worth a shot to see if it resolves the problem.

If the Eaton was a new loaded posi and not checked out of the box it will have fiber clutches in it. Those don't usually chatter until the fiber is gone and then there's nothing by slop in them with the heavy spring tension. If they were replaced with solid steels those should work once correctly setup. I have used 4-5 new loaded posi's this year and would never use them as is out of the box. I took one apart Monday in fact and once the spring pack was removed the Left side had endplay and the Right side was tight. I never use the spring packs in posi's and run them in about 800 times on my machine before they enter the diff housing. I also never use fiber clutches or snowflake type.

Gary, I just checked my December, 2017 paperwork, and it appears the Eaton posi was installed out of the box in the carrier with NO additional steel shims quoted. So I now have a nearly 5 year old posi with just a little over 1000 miles on it that chatters. Honestly can’t recall if I did the figure 8’s when I recently added the additive to the original 5 year old Royal Purple oil or after I changed to the current Shell oil and the additive. Obviously my next step will be doing the figure 8 routine. Jack J.