2001 2500HD 4x4 6.0ltr 4L80 crew cab

Got home from a long trip last week. Got outof the truck and heard what I thought was a valve train issue. Parked the truck and walked away for a week. Crawled under it while idling yesterday and the noise sounded like it was at the flywheel. The "knock" is constant at this point.
Put the truck inthe garage to investigate deaper today and at first it was constant at idle, but went away w/ some rpm's. Got under it today and it really sounds like it is coming from the trans. It also is not constant w/ the idle rpm. It will do it randomly now. Sometimes w/ more RPM, sometime not at all.
What in the trans could cause this?
My plan is to drop the dust cover and disconnect the converter from the flywheel and see if it still does it.

 

Sounds like this?


http://www.youtube.com/watch?v=kxbYh...e_gdata_player

This was a cracked flywheel.

 

Sort of.
I got the cover off and rotoated the flywheel and I couldn't see any issues w/ it.

How in the hell do you get the converter bolts out?

 

That vid has more of a scraping sound to it. Mine is more of a ticking.

 

I could only tell the flex plate was cracked by little hair line cracks in the round circles of flex plate.

You'll have to pull the starter to get to converter bolts

 

Flex plate

 

I got the converter disconnected and it does not make the sound now. I guess it is external of the motor.

Who makes a good replacement?

 

Good replacement for what? Flexplate?

 

I'm starting to hear banjo's playing.....

I think you should check the flexplate.

 

Yes the flexplate.
I also was finally able to see the crack. I connected everything back up and the knock was back. I need to have it drivable so I can get it to my buddy's shop to use his lift and trans jack to swap the flexplate out.