Join Date: Sep 2000
Location: Washington, Michigan USA
Only the lower bushing is exposed to engine oil; the upper bushing is lubricated by special lubricant enclosed in a well in the top of the housing under the segment ring - the well has a plastic seal and felt pad between it and the pickup coil. The plastic seal has probably worn out, allowing lube into the housing area. Usually the lube in the upper well just dries out and wears out the upper bushing, as almost nobody knows this lubrication well is there and doesn't last forever, unless they've read the distributor portion of the Service Manual.
'69 Z28 Fathom Green