cajones2
Member
99 600sx Crank Mandrel Discoloration (Bluish) - ** See Picture **
I was wrenching on the sled last night and had taken the carbs off and pulled the reeds out. I noticed that on the PTO and the middle cylinder where the pin fastens the rod to the crank mandrel, was some blue discoloration as thought it had gotten really hot at some point. The MAG side did not have any discoloration, and the funny thing was is that the discoloration only happened on one side of the rod, not both. If it was a bearing, i'd suspect that the pin would get really hot and both mandrels would be discolored. The bearing from what i could see looked good too. I am pushing 3800 miles on the sled. Here are some pics of what I saw.
Does anyone know if this is a problem or what the cause is/was?
Thank you all in advance!
Craig
I was wrenching on the sled last night and had taken the carbs off and pulled the reeds out. I noticed that on the PTO and the middle cylinder where the pin fastens the rod to the crank mandrel, was some blue discoloration as thought it had gotten really hot at some point. The MAG side did not have any discoloration, and the funny thing was is that the discoloration only happened on one side of the rod, not both. If it was a bearing, i'd suspect that the pin would get really hot and both mandrels would be discolored. The bearing from what i could see looked good too. I am pushing 3800 miles on the sled. Here are some pics of what I saw.
Does anyone know if this is a problem or what the cause is/was?
Thank you all in advance!
Craig
Last edited:
SWEDE
New member
I noticed the same thing on mine recently and exactly as you have described.I think that its normal, but am not positive maybe one of our resident experts will weigh in soon.
cajones2
Member
Maybe it is that way as a result of assembly?????? It just makes it look like it is on the brink of nuclear fusion with the heat marks. Had I not noticed it, I would never have known there was a problem because everything is working just fine. Like you mentioned, hopefully one of the pros will chime in so we can sleep easy at night.
blueblooded
Member
Mine is the same way also.I was worried at first too but after doing some research on this forum i learned that it is normal.From what i read it turns blue from the forging/heat treating process.
Yea I have two spots like that on my crank. You can see them in my working log thread. That is just from when the crank was manufactured together.