First, I would only remove the headstock from the bed as a last resort.
The main requirement on the grease for the open gears is that it should be rated for high temperature operation, at least 300 degrees F. The original factory recommended grease hasn't been made since shortly after the French company Total bought the maker.
Also, there is actually no such thing as a 30 wt grease and never has been. The proper oil to use where oil is specified is SAE 20, not SAE 30. The ISO equivalent is ISO 68 if you have trouble finding SAE 20 ND. It may be described as hydraulic or circulating oil. Do not use multi-viscosity motor oil, not because it is multi-viscosity so much as because it will contain an additive that absorbs moisture from the atmosphere and never gets hot enough to blow it out the tailpipe as it does in an engine application. Also, oil described as "way oil" is OK to use on the ways and the carriage and tail stock gibs. It will stay on or cling to the vertical surfaces of the ways better that straight SAE 20.
The bull gear is not free wheeling for the simple reason that it is locked in place on the spindle by a Woodruff key and a set screw. The pulley on the spindle is free wheeling relative to the spindle if the Direct Drive pin is pulled out. And what looks like a set screw in the (in the case of a cabinet model lathe) 2-groove pulley is actually an oil plug. It MUST NOT touch the spindle when tightened. This is an unfortunately fairly common error that too many new owners make.
On the subject of manuals and parts lists, there are several in our Downloads module. Along with drawings with which to make some of the NLA parts. But access to Downloads requires Donor status (and reading the instructions for use). The best manual on the late 12" happens to be the one on the Atlas 3996, which differs from the 101.28990 only in having Atlas on the badge and nameplate instead of Craftsman. It is a pet peeve of mine that very few people who have a scanner have even a clue as to how to operate it. One of these days I may find the time to clean up one of the Craftsman manuals and correct several minor errors in it.
