HELP! A904 skipping 2nd gear.

Tony is likely correct about something possibly breaking or coming loose but I think before I yanked the pan I'd try just adjusting the front band. The adjuster for it is on the left side above the linkage. You tighten down the adjusting screw to 72 inch lbs then back it off 2-1/4 turns and lock down the locknut making sure the adjuster didn't turn with it. If the adjuster screw just freely screws in all the way that's a sure sign something Tony mentioned is the problem.