1997 Geo Metro 1.3
 

Swapped out motor and have cracked out two flex plates. Anyone experienced this before or have any ideas on the cause?

Thanks
Dan

Seems to me that cracked flex plates have been an occasional occurrence with GMs for many years.
BUT
... If you've had 2 in a row, I'd want to make sure that there is nothing between the block and the transmission housing that stops them from mating up correctly - rusted dowls or something. If it is all clear there, then I'd check the space between the crank and flex plate, then between the flex plate and torque converter. Don't forget to rotate the converter and check each mounting tab in relation to the flexplate.

Thanks for your response. The Trans/block connection was clean and tight all the way around. Flex plate and crank had a clean fit. I will check the torque converter centering piece and its fit into the crank.

Thanks again for your advice and I could not agree more with your quote.

Thanks.

The centering of the TC in relation to the flywheel is one direction, but suppose one of the tabs on the TC is bent slightly toward or away from the transmission - so that when you bolt it up one tab pulls (or pushes) the flex plate so that it spins like a warped record album. If you already have it bolted up, and can see the flywheel while its running, you might check to make sure it is running true.
ps. I don't know if the book calls for it, but I always use loctite blue on the flywheel bolts.

Thanks. I will take a look at those as well.