Our brand new transmission seems inordinately noisy to me.
It is mounted on an engine with less than half the rated HP of the transmission, so it is not overloaded.
The noise is like a fairly high pitch rattle, and is louder than the engine noise when you are in the engine room.

We have checked the usual stuff, oil type and level, gear shift position etc
It is not overheating, and there is no whine.

Tomorrow I plan to pull the oil filter and see whether there are any metal particles in it
Ditto with a small sample of oil from the bottom

Are ZF transmission usually noisy?

Any other things to investigate
I am talking with the vendor of course, but want external opinions