I had the same problem but I did heat the gear during original assembly. I received the same advice, to heat the gear and all problems would go away. What I did to be safe was drill and tap a 3/8" UNC hole into the middle of the cam and used a short bolt with a large washer so there is no way of it can walk off. But the bolt head will contact the inside of the cover, so what I did was turn a frost plug upside down and weld it to the cover and drill a hole where the bolt contacted the cover, and everything was fine after that.
