SEAL-rider
Active Member
I was visiting Curtis at WSW this weekend and had the opportunity to help him open the primary of a Chopper than was making some noise that sound like a bad rod knuckle. But after pulling the primary cover Curtis discovered the sprocket nut was hand lose. I asked him how that could be if it had been torqued properly. He explained something many of you already know, and those of you that don't need to.
Many of the washers used in an engine or transmission or primary are under tremendous pressure. The sprocket nut is torqued to 150 pound ft. If the assembler or mechanic is lazy and runs out of through hardened washers and just grabs one that looks the same bad things can happen. Under high torque and constant force the washer can deform and allow the nut to get lose. He is a picture of the case hardened washer Curtis pulled out of this bike. It is grossly deformed.
So what is the difference is through hardening and case hardening. Case hardening is only surface hardening, and through hardening goes completely through the part keeping it from deforming. Make sure your mechanic is using through hardened parts when required.
Many of the washers used in an engine or transmission or primary are under tremendous pressure. The sprocket nut is torqued to 150 pound ft. If the assembler or mechanic is lazy and runs out of through hardened washers and just grabs one that looks the same bad things can happen. Under high torque and constant force the washer can deform and allow the nut to get lose. He is a picture of the case hardened washer Curtis pulled out of this bike. It is grossly deformed.
So what is the difference is through hardening and case hardening. Case hardening is only surface hardening, and through hardening goes completely through the part keeping it from deforming. Make sure your mechanic is using through hardened parts when required.
