87 Ranger 2.9l manual trans.
When engine is running, and the clutch pedal is NOT depressed, there is a distinct clunk/thump/knock noise that is directly related to engine speed regardless of selected gear. If you puss the clutch pedal, therefore disengaging the clutch from the flywheel, the noise goes away.
We had the transmission rebuilt at a trans shop, they replaced all the internals of the transmission. Reinstalled the transmission ourselves and now this noise is occurring.
The noise is definitely coming from inside the bellhousing. With a stethoscope you can hear it wishing bellhousing rather than engine block/oil pan or trans case.
Any info/suggestions would be appreciated. Thanks

 

I would first check the U-joints, especially if it only makes noise when in gear clutch pedal out.
If it makes it in Neutral with clutch pedal out I would suspect input shaft

Out side of that I can't think of anything that would clunk in the bell housing with clutch pedal out