Hi, I have a 98 Accord V4 sedan, runs fine, has got 113K on it, just passed honda inspection with flying colors. Recently I have noticed that at high speed (above 65 mph) it make noice as if it is running one gear below the top gear and it feels like soon it will change to top gear after some distance and the noice will become normal but that never happens.

I checked several times on freeway and it changes all gears at appropriate time and speed and the rpm is perfact too.

However when I am driving slow (15 mph or so ) there is no noice at all and everything is perfact.

Any advice is highly appreciated.

Thanks