<VV> Howeling noise from Clutch

[Michael Baiamonte]

My Dad and I replaced my pressure plate and clutch disc recently.  While we had the engine out we also replaced the throwout bearing and input shaft seal.

However, now when I start it up after it has been sitting overnight or for a few hours, the clutch makes a howling (whinning) noise when I insert it for the first few times.

Did I put something together wrong?  I can't think of any other part I could have replaced except the pilot bushing.

Help.

mike