98 Z28 A4

Makes a clunk shifitng into 3rd gear (2nd to 3rd) under light load. I know it is in the tranny because it does not happen utill the tranny warms up a little after starting. Also, I recently changed the tranny oil, as part of my regular maintenance. The clunk when away for about 2 weeks and then came back.

I am thinking of trying some tranny additive that might help restore seal, orings, etc. There are many available at the local parts stores.

Anyone know about these products? Good idea? Bad idea? Any input welcome.