Clunk noise on the 1/2 shift in an A999 trans.

What has to let go to make the 1-2 shift?
I have only taken apart a few 999s but all of them had a badly worn bushing in the 1st gear planetaries that could cause a whining noise.
Just replace a bushing in one a couple weeks ago , it was totally sloppy in there leaving only the planet gears to pilot the assembly.

The low/rev servo and rear band.
That's why I suggested loosening the front band a little so it gives the rear servo/band more time to release before the front one takes hold.