Reply to "Chainging ZF Oil"

Recently I had the opportunity to change the oil on my ZF (thnaks to Lloyd's info). I haven't changed the oil since I purchased the car so I don't know how long it's gone without an oil change.

That said, the oil drain plug had a lot of thick grease around it with what seemed to me, like a lot of metal shavings in it. No big chunks, just a ton of small shavings.

Is this normal?

And since my ZF shifts smoothly with no grinding in any gear, is it safe to say that my ZF should last another 30 years with no problems?

Thanks for the info!
Bob Eaton