Good luck

 

you can inspect for any unusual noises when you rotate the inner shaft, or look for signs of metal shavings in the transmission fluid. If you're unsure, it might be best to have a professional mechanic take a look before reassembling everything.

Good luck with the engine swap! You've got this.

 

So metal shaving is not unusual BTW. for the life of an automatic transmission as parts normally wear. Now large pieces of metal or other material are cause for concern but then if you are that far by dropping the pan then there are other telltale indicators of possible problems. And unless one is VERY experienced rotating the inner shaft as you described is not a very good indicator of a problem.
As fr a professional "mechanic" most are not well vised or experienced in automatic transmission diagnosis when they are apart. In fact, most when there is a problem will usually start giving estimates to replace the transmission or having your rebuilt and then they install it. Main reason is there are specialized tools required.

 

Tools to listen and help locate unusual or unidentified noises from any area of a vehcle.