If you remove the cotter pin and loosen that slotted screw in the drag link it will let go of the pitman arm. You don't have to separate the pitman arm from the box unless you're replacing the seal or rebuilding the box. Here's that page in the shop manual:

http://chevy.tocmp.com/1948_51truckshop/51ctsm0304.htm


1952 1300 Canadian 1/2 ton restomod
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