Rejected crank

[MooneyTunes]

19 minutes ago, redbaron1982 said:

Who deemed it un-airworthy? Lycoming?

If Lycoming replied "hey, yeah, that was us when doing hardness test back in the day" and it ended up inside your engine, they at that point it was airworthy, so why would Lycoming now, without any additional data, say that's not airworthy?

It was deemed un-airworthy by the repair shop inspecting the crank. They based their decision on Lycoming SB 475C figure 7. 

[MooneyTunes]

26 minutes ago, jamesyql said:

I’m sorry to hear this. I don’t know your reasons for needing an overhaul, so don’t take this to second guess your situation, but zooming out to a high level- this is a general good reminder to us all that if it ain’t broke, it often doesn’t need to be fixed.

The engine started making metal.

[jamesyql]

The engine started making metal.

Best of luck with getting this sorted out and back in the air.

[AndreiC]

I would talk to Lycoming and ask them, for a crankshaft like yours where hardness testing was performed, where should the minimum space be measured, at the slightly indented area or in the rest of it. Seems weird that the shop says that there was an improper repair made to the crank when said part was installed by Lycoming.

[MikeOH]

If it was me, I'd have the Fig. 7 dimension re-measured by someone else (I might try myself, but that dimension looks tricky to measure to 0.001" with home shop tools).  And measured in the undisturbed area, not around where the dimples are. You might even ask the shop that rejected the crank exactly where they made the measurement.  What I'm getting at, is that if this is a first run crank, which given the factory dimples are still there, it appears to be.  Then, I don't see how the Fig. 7 dimension could have become out of spec; the gear locates on that surface and is fixed by the locating pin, so I struggle with how it would get worn beyond the limit.

[LANCECASPER]

3 hours ago, MooneyTunes said:

The engine started making metal.

A few times I've heard of Lycoming accepting  a core and giving full credit when it didn't exactly fall under what's usually acceptable. That may make the price of an exchange a lot closer to what you'd pay when you factor in a new crank and camshaft and case or whatever else they find. Of course Lycoming's timetable may be too far out for you. 

[MooneyTunes]

5 hours ago, LANCECASPER said:

A few times I've heard of Lycoming accepting  a core and giving full credit when it didn't exactly fall under what's usually acceptable. That may make the price of an exchange a lot closer to what you'd pay when you factor in a new crank and camshaft and case or whatever else they find. Of course Lycoming's timetable may be too far out for you. 

I will definitely pursue some kind of resolution from lycoming. New cranks are very difficult to find nowadays. Even yellow tagged ones are hard to find.