Yeah its the 2nd generation of Outbacks, but 3rd generation of Liberty so we call it Gen 3. Its a BH model - ran from 1999-2004niterida
Before we give you some advice on your shifting issues.
Your model is the same as the 2nd gen U.S. spec 2000-2004, correct?
What engine do you have?
Besides the shifting issues, is the rest of the vehicle mechanically/electrically sound?
Its a 2.5 SOHC NA - engine has been recently rebuilt so is strong and mechanically good. No other major problems. It did exactly the same with the standard box that failed after 330,000kms (200,000miles) - replacement box was from a 1999 Turbo Forester with similar transmission code (not exactly the same but it was just the last couple of numbers and I believe that doesn't matter) and it plugged straight in. So it is something outside the box and I assume it is the TCU - or are there other sensors or anything that could affect the gearshifts.
My sister has a 2001 Outback that is as smooth as - I swapped her TCU in to mine and it was better but still not as good as hers.