I've noticed that there's a strong vibration between 1st-2nd and 2nd-3rd both at 4,000 revs. 3rd-4th and 4th-5th sounds fine.

If I accelerate slowly in 2nd, the engine noise sounds OK; as soon as I get to 4,000 the vibration starts instantly, then dies as sound as I'm past 4,000.

Any ideas? It's quite strong, I can feel it through the pedal and even the dash vibrates !

It's been there ever since I can remember.

Stefan