Pilot bearing mishap

[steveoelo]

So read through the tech article and discovered that the pilot bearing location on a 2.9 is in the flywheel. If someone were to have put this in the block, would that cause a grinding noise? Only makes noise in certain gears at certain speeds

 

[pjtoledo]

a pilot bearing is the go-between for the crankshaft (engine) and the input shaft of the transmission. while driving, both the engine and transmission are turning at the same speed, so the pilot bearing is rotating with the 2 parts but it is not spinning as a bearing.
the pilot bearing is only spinning when the clutch is depressed and the engine and transmission are at different speeds. so they usually don't make noise when driving at a steady speed.