automatic tranny question

Hi,
My 97 k1500 developed a strange symptom yesterday.
From neutral to drive if feels normal, but from reverse to drive or drive to reverse, there is a double thunk instead of the normal one thunk.
Like there is play in there. It drives ok so far though.
Any thoughts?
Thanks
Bob B

Our trucks make lots of clunks when it comes to the drive train. I was told don't worry about it. You can check the universal joints on your drive shaft ,this is where you can take out some of the play if the joints are bad ,otherwise drive it.

Kevin