Stuck posi clutches

[supercar]

I had a Trans Am when I was a teenager that had noisy posi clutches and I went to the Pontiac dealership and talked to the old mechanics about how to fix it. They told me to put in a bottle of GM additive and do a burnout with the right wheel on the grass and the left wheel on the pavement, then do a burnout with the left wheel on the grass and the right wheel on the pavement. I did and no more noise! I have used that trick for years on many cars and trucks. I miss those old days when you could go to the dealership and talk to the mechanics and they would be glad to help a broke kid fix his car.