Auto Parts: Transmission, shaft bearings, clutch components

Question
I just put a new clutch,pressure plate and throwout bearing in my 95 Nissan XE 2.4 ltr 5spd 2-wheel drive pickup. When it is in neutral I hear a grinding marble like sound. I push the clutch in it stops. Is that my input shaft bearings going out.

Tony Frederick

Answer
    No, I doubt that it's the input shaft bearing.  It's one of two things.  Most likely is that the throwout bearing that you used is either bad or the wrong one.  When the clutch is released, the bearing should pull clear of the fingers on the pressure plate and just sit there.  It sounds as though yours is knocking against the pressure plate, not hard enough to turn properly, and bouncing off of it, making noise.  Another possibility is that the collar on the bearing, or possibly the sleeve that it sides on, is knocking against the driven disc when the clutch is engaged.  This is a good time to review whether or not you installed the disc right-side-out.  The disc is usually marked as to which side faces the engine.  If it is put in backwards it can keep the pressure plate from engaging properly.  It is possible that the input shaft bearing could be going bad, but it is supported by the clutch assembly when the clutch is engaged and will rarely make noise.  As much work as it is, I would be tempted to take the whole thing apart again and compare the new parts to the old ones (if you still have them).  If there are any discrepancies you should go back to the parts store and find out what is up.  And, just for kicks, rotate that input shaft by hand and see if everything's nice and tight.  It's also possible that one of the other bearings or synchros associated with the input shaft could be bad.  It would be helpful if you could listen carefully and find out where the noise is coming from.  Still, if it didn't do this before the clutch change, then the clutch, or one of the clutch components, is almost certainly to blame.