GOLD further onto the explanation of the cam gears.... I don't know if it the cause or effect. Could be that the bolts were loose, causing the cam speed to dart back and forward, causing a bearing failure. Could be that the cam seized slightly, turned the cam gear, loosened the bolts and kept going. If there weren't any alloy in the oil, I would have said the gears were the only issue and put it all back together. I really hope it's all it was and the alloy is just residue from the last machine. But...... I want it checked now, while it's all apart. Better safe than sorry.