Just my 2 cents. I tried RedLine and another product and I didn't notice a difference. If it did have a quiting effect it must have been minor. My conclusion in my case is fix it or live with it. I have heard others state that it may last a long time before an actual failure. I've been living with it with fixing options consist of new replacement from dealer $3000.00. Junk yard $350-500. 91 300E 4matic LSD Diff. I thinking of selling it in the spring, since it's my winter beater.