figment
A junkie for the purr of a 6.5L
To me that's one of the signs of major trouble, that metal particles is the from either the bands or the main pump in the transmission were wore, out. You said that you only got to drive it a few yards is an indication that the pump was probably too far gone and just gave out.Sorry to now make you feel nervous.
My 4L80E did the same as yours. I dropped the pan and changed the filter... there was some metal debris in there.
I was told this too on one of my other vehicles and for a second opinion I brought it to a mechanic that has rebuilt tranny's for 30 yrs. He just chuckled. He also told me when it starts to give trouble when there is no oil leak he said it's usually too late.Tranny shop told me all the junk in there made things bite and when I flushed to new oil it killed it.
My owners manual say's it should be changed every 60,000 km's I think, so if you've got 100,000 on the fluid it should be changed especially if you tow anything for extend periods of time.