My car is a 2004 3.0R SpecB.
So there's been a noise progressively developing somewhere on my car. Tyres needed replacing and thought it could have been those but turns out it wasn't. Then I thought it was a wheel bearing so I put the car on a hoist and checked all four corners for play, rear left had play so I booked it in for a new wheel bearing/hub. I go to pick the car up this afternoon and the mechanic tells me that the noise is still there but that the wheel bearing was definitely making noise. So that's one problem fixed but the original noise is still hanging around. The mechanic reckons it's coming from the centre diff, though I'm not sure how he came to this conclusion.
The noise doesn't change with engine RPM but is influenced by road speed. Driving at 110KM/h and putting the clutch in means the noise slowly decreases as speed comes down. As far as I can tell it isn't affected by the car being cold or up to temp.
Around the same time this noise developed, a vibration that only occurs around 40KM/h also made itself known. This vibration isn't affected by selected gear or by the car being cold or up to temp either.
So my question is, do the centre diffs tend to make a quick, sort of 'pulsing'-like noise and cause vibration when on their way out? Has anyone else experienced a similar noise or vibration in their Spec B's?