I just looked at my 48 WD and the AC parts book. What I believe you call a "cap" is the cross shaft "collar" which connects the horizontal shaft with the vertical one and the carb linkage. This collar has a tapered pin in it to hold it tight. You may have lost the pin or it has backed out enough to give you the slop. There should be absolutly no movement in this collar on the shaft. Check that out before you try to go into the governer!