just hopped in my car today, and heard a loud knocking, thought it was the engine. i have an 87 with a t5 that just had the whole clutch assembly redone less that 5000k ago. so i put it in neutral, and while doing so it got quiet. so it knocks when the clutch is out, and is quiet when the clutch is pushed in all the way? i was thinking either the pilot or throwout bearing, anyone else have any ideas before i rip into it?

 

I think its neither...

Input shaft bearing is my guess from what your describing.



Pilot would make noise when the crank and pilot shaft spin at different speeds, throwout would make noise when clutch is applied.


So clutch out = input shaft pinning same RPM as crank, throwout not contacting/spinning

Clutch pressed= input shaft slowed/stopped, shaft spiining different RPM than crank. throwout in contact and spinning.


What you describe is something further on down the line, being that the input shaft has to spin to make the noise.

 

, AHH good call, how sure are you on that, i dont have much experience in driveline, other that changing fluids.
noone thinks it could be the transmission do they?

 

Well from what you describe it does sound to me like its the input shaft bearing or possibly something further on down the driveline inside the trans.