Shortly after buying my car (used, 55,000 miles) I noted an occasional "flare shift" (briefly missing the gear). I had the trans. serviced by a Volvo specialized mechanic. He suggested replacing the accumulator also, which for a period of time seemed to have fixed the problem. Sadly the flare shift returned and seemed more common. I elected to add a small amount (6 OZ.) of Trans-X Which has cured quite a few minor problems for me over the years. In this case I immediately started completely missing 3rd gear. I drained and replaced the fluid with the approved fluid; no better. The only way I can now drive the car is to run firmly up in 1st and 2nd, then let it "miss" 3rd gear & go straight to 4th (a few seconds later). If I slow down to 3rd gear speed, the car fails to engage until it coasts down to 2nd gear speed.