I have a 2006 F350 6.0. I went to replace the oil filter with a brand-new Motorcraft FL-2016 filter, only to find that the oil filter return tube would not retract, thus I couldn't install the housing cap. This appears to be due to an engineering change to the filter, where Motorcraft eliminated the 4-point keyway inside the top of the filter. Attached are pictures of the new filter (no keyway) and the one I replaced (with keyway). Here's a YT video describing the problem