[miker98038]

I know different units require different additives, and my current ford experience is with an old Dana 44 in my bird. Probably different. But right after they outlawed whale oil I remember having problems with a posi unit. The answer was more additive, the new stuff wasn’t as good as the whale oil. It was just a couple ounces in that case.

You might check the specifics of what you used with the oem Ford (assuming it’s old ford parts) recommendations. If it’s aftermarket clutches, they may have a different spec.