Hi all.  1.8 petrol.  Feeling a vibration through the drivetrain? when car gets above 40MPH.  If I steer left, like when coming off a roundabout,  it goes quieter and vibration intensity drops.  If I go straight or steer right, no change in intensity of vibration or noise?  Thinking NSF wheel bearing but wouldn't it get louder when I steer right and transfer weight to the nearside?

Car's on 146,000.  Did gearbox oil at 120,000 when I bought it and again at 140,000.  Due M.O.T. in a month so not sure whether it's bearing or diff / gearbox.  Are the IB5s prone to failure?  Also, if I went to scrappie to pickup a hub, does it have to be from a 1.8 or are the 1.6s / 1.8s intechangable?  Are they easy to change.  Been a Vauxhall Astra owner for years and could change a strut / hub in 25 minutes.  Just wondering if Focus are similar?  thanks in advance.

Got this fixed.  It was the top engine mount, the one by the alternator pulley.  Can't believe I nearly scrapped the car for a £23 mount.  Fitted today, vibration gone.  Driving like new.