I drove the car the other day for the first time in a while, and was frightened to hear a clattering noise in the drivetrain. It is a clatter that seems to be active when even a slight load is on the motor, but not evident at idle or cruise. It seems to be coming from the tranny / bellhousing area. I immediately thought it was a flex-plate bolt coming loose, and clattering against the inspection cover (thats exactly what it sounds like), but when I pulled the inspection cover I found all bolts to be tight and happy. There is a slight rotational mark on the inspection cover, but none of the flex-plate bolts seem to have reciprical marking and that mark on the flex plate could be from years gone by ????.

Everything else seems to look good. I checked the starter bolts and all the bell housing bolts, all are tight. Rear tranny mount seems good. Motor has a Moroso solid mount on the driver side and a rubber stock mount on the passenter side, both look fine and the motor does not appear to be moving.

What else could be making a clattering sound that would sound just like inspection cover clatter????

Does the car need to be moving or does it do it while
sitting still

flexplate cracked?

what kind of flexplate are u using?? stock one's crack. i'd look there first. seeya.

Stock flexplate. never did it while sitting, more when the car was moving. I'll look the flex-plate over real good. Where do they tend to crack?

seen them crack between the large openings

Well, took a good look at the flex-plate. I don't see any cracks or issues. I think I'm going to go drive it without the inspection cover and see if I get the noise or not. If I don't, then at least I know where its at. If I still get it, then I know I'm barking up the wrong tree.

might as well take a good look at the U-joints while your under there.

Sure sounds like a cracked flex plate the way you describe it. I have seen flex plates with hairline cracks that make alot of noise but you cant see it until you take it off. Good luck , Ron

Well, I took it for a drive with the inspection cover off, and the noise went away. Tried to reinstall it, immediate clatter. I can see where the bolts are hitting the cover, and it donned on me that the cover is original to the car, which originally had an 11" converter. There is a channel stamped into the cover that follows the path of the bolts, and with the 10" converter that is in it now, the bolts fall inside that channel.

However, I still don't understand why this would just all of the sudden become a problem. Could there be something going on with the converter or front pump that is pushing the converter forward?

the pump can't push the converter out. if u have tons of crank end play, the bolts would hit the block first. i don't use a cover, so i don't know if the bolts can hit the cover before it hits the block. check ur end play. i beleive 10 thou is the max. seeya.

The conv could be balloning... just put a washer
under the 2 bolts to move the cover out or just bow
it out some
EDIT
Like said... check the end play on the crank