Crank hardening

[ikeG]

Had a crank ground that I had laying here that had spun bearings. Its done at machine shop but I am now getting mixed reviews on whether it should be hardened or not. Anyone have experience with hardening or running without? Plan was to have a spare block and crank ready in case of failure in pull truck. So in one breath i figure to not worry about it but i also figure if i have a use for a spare i would need it to last a little while.

 

[c20elephant]

Page 8 the author states.

The downside is that the affected area is very shallow and ANY undersize grinding will require​

the crankshaft to be re-nitride treated. This is NOT an option: if the crankshaft is not re-treated it​

will fail 100% of the time. There are even those of the opinion that too heavy of a polish will​

give you an issue as well, so the handling of these crankshafts with the utmost care is critical.


http://www.sbintl.com/tech_library/articles/rebuilding_the_6.6L_duramax_diesel.pdf

 

[PureHybrid]

Not sure what process (if any) gm uses on the dmax crank, but I would have it nitrided. Might help tighten up clearances if need be. Gm nitrided quite a few cranks on the SBC platform.

 

[RHallenbeck]

From memory GM started with Tufftride then went to Nitride.. I think there is a lot Cryo treating being popular now as well..

Rick

 

[ikeG]

Machine shop we now use says that he wouldnt be concerned about the hardening being affected due to grinding. The hardening would have penetrated much deeper than grinding .010" off which is the biggest bearing you can purchase for a duramax. IIRC

 

[delong_1]

My shop said the nitride does not go that deep and wouldn't ever run one without being retreated

 

[Burn Down]

My shop said the nitride does not go that deep and wouldn't ever run one without being retreated

I have heard the same.

 

[PureHybrid]

Not sure what process other places use, but when we nitride cylinders its for 8-12hrs depending on how many are loaded in the machine and vessel temps reach 1000°F. IMO it does more than treat the surface, but if we bore a cylinder because of an assembly issue, it gets rerun through nitride process.