[dizzyD]

I have a friend that had a CAT go out, at first he thought the torque converter was bad when he heard that noise.
Just an idea :?

 

[dizzyD]

The t/case is chain driven between the input and output to the front driveshaft. The chain could have stretched enough to be rattling in the case. Not an uncommon happening. Usually not noticed until the case comes apart, either for maintenance or because it blew out.

But that should only happen when in drive and moving, right? He's in park when the noise happens.