put new vibratech damper on. drained the old stock one.

I'm not sure either, but good idea to change it. Thanks for sharing!

 

Never thought of drilling holes in my old one. Thanks for the pics. Grab the cutting wheel and then take a few more shots!

 

OK, I'll play. I changed mine also, at 1 million miles on a C15, 6NZ, no difference.
I took a metal cutting bandsaw and cut mine in half just to see what's going on.
The "oil" looked just like yours, really thick and real slippery if you will. I personally can't see where anything can go wrong. The only things I can imagine going wrong is: Housing is damaged with either a dent that would restrict the rotation of the inner ring or a breach of the outer housing allowing the "oil" to leak out, or the inner ring broke somehow. Either of which would be obvious in vibration or mess.
Granted, if I were rebuilding an engine the damper would be replaced as a maintenance item. I feel I wasted my money.
BOL, to you.

 

I would think there is a way to test them or check them, but I also think they have to be removed first. If they have that amount of time on them and you have to remove it anyway, you might as well replace it. I do think that fluid can dry up and become hard or at least not as fluid and cause problems. I feel way better having parts that perform to 100% of what they are suppose to do, not 70% or less.

 

How hard was it to change out? I have a new one in my office for my truck and have yet to tackle it.

 

so its just a unbolt rebolt on deal?