Broke down roadside Can't find the clatter/rattle

[Enigmatic Nomadics]

308k miles on Thomas Vista 3600 Handy with T444e 175HP sending power to a AT545 transmission.



Coming around a downward bend a loud clatter began so I pulled over to inspect things.


So far I THINK I have ruled out the following:
fan clutch


All pulleys. (Sound still present with belt off)


Injectors. (Temp remains the same on all cylinders using laser thermometer)


The turbo has no play and is dry


I BELIEVE the flex plate is okay. I removed the tranny, torque converter and Pulled the flex plate and a visual inspection appears that it is fine. (Nothing close to what a damaged one looks like on line)

I also ordered in a Scangauge D and was throwing no codes before I tore into things.

I have the tranny on jacks about 10" from the motor and can't figure out what the problem is.

I removed the flexplate because the sound was exactly like the one in the video.

https://www.youtube.com/watch?v=-Ee5G5P17xM

Looking for further suggestions.


Thanks,

~Jamie