The AN-8 oil return plug in the Lycoming accessory case behind the governor mounting pad on the outboard side is a bitch to remove. I broke 4 sockets trying to get it out. I heated with heat gun. No joy. I heated it with my propane torch at least three times. Maybe not long enough but it seemed long. The engine is such a heat sink, that the heated area cools extremely fast. I sprayed penetrating oil on it hoping it could work its way in. I earlier sawed a 1 1/2 inch piece of 5/16 hex wrench and inserted it in a 5/16 1/4 drive socket. Split the side out of that socket. Tried it again with a deep well socket and twisted the 3/8 to 1/4 adapter right off. Went to straight 3/8 drive and bought some Kobalt hex sockets (one 5/16 and one 8mm). Both of them broke. We're talking using a16 inch 3/8 drive wrench, a 12 inch extension and the socket hexes. I'll retry later after I cool off. I haven't broken 4 tools in 20 years. Maybe my air hammer wrench....
Thats the large NPT plug. Lycoming put it there 35 years ago.
Disasterous results. Broke everything.
Knew it was risky with 1/4 drive adapter and socket but tried.
