Stihl MS201TC Crankshaft case hardening problems

[Creaky limb tree care]

Anyone ever come across this before? had small end bearing issues on the 201tc but never seen this! (excuse the double pic of the same image )

 

[av8or3]

That crank looks nothing like the one I just now put in a 201tc . It almost looks like it was made that way. I don’t believe crankshafts are case hardened tho, that would make them hard as heck for a few thousands on the outside but soft in the middle.
The bearings and seals I replaced were packed with sawdust and dirt, but no damage to the crank really. The surface where the clutch bearing was was slightly discolored but I was able to rub that out with crocus cloth. I really don’t know what to think about your 201TC crankshaft.

 

[Al Smith]

I have no idea how those things are assembled but might add some areas on automotive crankshafts are induction hardened .That process in some cases will "run the colors " .

 

[Creaky limb tree care]

I have come across hardening problems with the early ms261's crankshaft too on the clutch bearing race, correct me if I'm wrong but, I was of the understanding that these were case hardening failures, I can't understand how else they could fail like this?

 

[Al Smith]

I don't know what alloy the crank is made of but normally it takes about 1400 degrees to change the properties of most steel .That would be about the color of a pumpkin .I think there is more to the story but that's just a hunch .