Irs fluid capacity

[Jeff's First FFR]

Hi all,
Well, I drained the diff and refilled ti with Motorcraft 75W85 plus 4 oz XL-3 friction modifier. I was watching the fill hole for overflow. It took TWO QUARTS and nothing overflowed. I thought the spec is 1.6 quarts. What gives? It is a 8.8 center section with 3.55 gears. OEM from FORD via Factory Five.
Thanks in advance,
Jeff

[Railroad]

You are probably in the wrong hole.
Axle level?

[chjort]

I had the same experience when I drained and refilled mine. If you stick your pinky finger in the hole, you can probably feel that the liquid level is just below the hole. I called FFR and they said that as long as you had added the spec amount, you were good. They said if you have more in there than the spec, its not a problem.

[Jeff's First FFR]

A case of "More is Better?"
Sorta like horsepower? and cubic inches? and "How you measure dat"? ( If you don't know that one PM me.)
Thanks,
Jeff

[Jeff's First FFR]

Every thing level. I'm pretty sure I'm in the right hole. But...then...

[edwardb]

As stated, it will be slightly below the hole when the specified amount is added. If you put in the right amount, you're good.