My car keeps cracking the flexplate. When I bought the car the previous owner told me it had cracked and he had it replaced. About two years later, it happened again. I found a used replacement and had it swapped out at a transmission shop. While he had it apart, I had him look around to see if he could see any issues that could be causing it. He checked the trans to engine alignment, and it seemed okay, as well as the endplay in the crank. About two years ago, it cracked again. This time, I had the torque converter in the trans replaced, as my trans guy said it was slightly out of balance. Now, it's cracked again. Any ideas what other things could be causing this? There are no obvious vibrations from the drivetrain at any speed, but I only seem to be able to get around 2000 miles before the part cracks. I guess I could just keep replacing it every time it goes, since now they are being reproduced (not true about two years ago), but at $175 plus the cost to pull the trans and replace the part, I'd really like to fix it once and for all. Thanks in advance for any ideas of things to check. Car has the original drivetrain (401 with switch-pitch trans), mileage is just over 69,000.
Keith