02 4.3L 4wd LS 92K

Recently got the trans serviced, fluid and filter, when climbing mountain road the other day, rounded a corner and stepped on it to kick the trans down for the hill, as it disengaged 3rd it made a metallic click, then when 2nd engaged, a loud bang. Repeatable.

Seems to be noticeable when power is applied rapidly. One would think U joint, but i cant see or feel any play in them when i rock the tires against the trans in park.

Also thinking of a transgo HD2 shift kit, opinions???

 

Ya something has definitely went wrong inside the trans. No ideas from me though.