About a month ago I bought a 86 Blazer. I had to Replace the rearmain Seal and I couldn't get it to seal off all the way. My dad told me to put a quart of Lucas Oil Stabilizer... Since it was leaking a Little and Shure anufe it stoped the Leak and it runs a lot Better. I don't know how it works but it does.. I would Recomend it to anyone.