Yes, the old AP-900 and AP-1200 mounts had nylon clutch (cylindrical) plugs, which do flatten out “into the narrow free space between the axle and the threaded bolt shaft. It ends up looking like a “mushroom” inside that tight channel space. At that point, with the nylon now partially jammed between axle and housing, it becomes very difficult, almost impossible to rotate the axle by hand. The flattened plug head can’t be extracted the same direction it went in, and it also mushrooms itself into the threaded walls of the bolt hole, so it becomes stuck into the wall’s threads. As I recall, the only option is to force the entire axle out of its outer housing, (using 3” long, screwed-in “push bolts”, from the axle top head-end), drill out most of its center to a thin walled cylinder, then hammer the remaining mushroomed nylon plug inward, for removal. Extremely difficult repair task.
I bought the AP extraction tool, which I was even advised up front, by staff that it likely wouldn’t work very well as it chipped the plug material. The tool is just a specially filed down screwdriver – and I followed the instructions. The tool just ate away at the old, compressed, now age-brittled plug with every turn of the blade and never got a grip on the plug for extraction.
In fact, it probably works in rare cases, of newer plugs that weren’t tightened down all that much over the years – certainly NOT using an Allen wrench on the axis lock down bolt head!
The guys at AP certainly deserve their well earned praise and admiration of doing such a difficult job in plug repairs. I don’t envy them at all, but appreciate their personal hard work.