I bought an 8.8 front diff with yukon 4.56 gears already installed for my 02 screw. I bought it off of a guy on this website and it came off of an 01 expedition. The diff is in great shape and I installed it on Friday. My only question is is my front diff had 2 vacuum lines that hooked up to the diff to disengage the gears completely, but the new one did not have to hookup to do this. Are there 2 different types of diffs that ford had?