Hi All, Looking for some input from other users here. A while ago I did a full differential fluid change. I filled it with the recommended type (75W-140 Motorcraft, no modifiers in oil) and amount and added the recommended 4oz of Ford XL-3 friction modifier. Everything seemed alright but I have noticed that the chatter in the rear end is back somewhat. I find that particularly on hard launches (even on straights), making even an average launch while going uphill from a standstill, and making a quick right hand turn from a stand still there is a decent amount of stuttering/chatter. At first I thought it was the drive shaft as I had to remove it to put a new gasket on the output shaft of my transmission, and it felt as though the chatter was originating from there, but everything appears to be in order there. As this seems to be a textbook case of not having enough friction modifier in your differential, would it hurt to add another 4oz of friction modifier? I have read some people having success with this while others are dead set against going above factory recommended specs. TL;DR: Chatter has developed. Has anyone added above the recommended 4oz of friction modifier to a Ford 8.8, limited-slip differential. Any negative consequences?