I have a 94 ex shell I put a z6 swap in, when I started the car I noticed a loud knocking noise coming from the transmission that would go away when I pushed the clutch in. I figured it was the ISB so I threw a known good trans in. Now the noise is still there but doesn't go away when I engage the clutch. I swapped out the throwout bearing with the trans just in case so I know that's not the issue. Is it possible the clutch, flywheel, pressure plate or pilot bearing could be causing the knocking? XTD stage 4 6 puck unsprung clutch fwiw. Car will go into gear and drive/shift through all gears without issue and I'm 99.9% sure it's not rod knock.

 

*could* be a bad thrust bearing.

Could also be a loose flywheel. Did you check all the bolts and things you mentioned when you had it sitting right in front of you as you changed the trans?

Why do you have that clutch in the car?

 

I checked to make sure it was all torqued to spec but didn't pull anything off and inspect it. The clutch is what came with the swap when I bought it.

 

That takes care of the torque specs but what about all the other things you should have checked for?

 

You would have to take the clutch off to torque the flywheel....

 

^^ I missed that!

 

I just pulled the trans again and the clutch/pp and flywheel. Clutch seems fine has plenty of life, flywheel and pp are smooth, none of the bolts were loose. Not sure what else to look for

 

Does the engine oil have metal shavings in it?

 

I didn't see anything unusual when I changed the oil. Would it be worth taking the pan off to check?

 

This.. I had the same issue OP is describing and that was the cause

 

Any way to tell without pulling the engine apart?

 

What torque spec did you use for the clutch and flywheel bolts? Do you have another good clutch laying around?

 

87ft lb on fw and 19ft lb for clutch. Nothing laying around but I'm sure I could get my hands on an oem clutch.

 

Pulled the pan to check for metal shavings, it's clean.. Going to pick up an oe clutch kit today, anyone else have any input before I throw it back together?

 

Not really bud. Hopefully the knocking was just the clutch. Hard to know since we haven't heard it.