cracked flex plate (flywheel)

I have a 99 s-10 with a 2.2 4cyl. automatic. At 58K miles the flexplate had to be changed because it was cracked all the way around at the crankshaft. The new NAPA one lasted till 71K. It was cracked in the same place. (Also changed the starter thinking this may be the problem) Still NAPA parts Now at 79K the third one is cracked. Has anyone ever experienced this? graffelf

I had a chevelle that had the same problem many years ago. The problem was due to a bent crankshat flange. I had bought this enegine from a salvage yard after all the important stuff checked out good. After about 10K on it, the flywheel would either do a slight squeal or a crunch sound. After going thru 2 flex plates I pulled the motor took it apart (Was going to mod it) pulled the crank took block and crank to machine shop where they informed me that the flange on the crank was bent. Needless to say that I replaced the crank.
John

Mine cracked we believe to to incorrect torque and pattern on the bolts when we swapped the engine.. New one has been fine ever since.

Here's what came out of my truck.

http://www.pghconsulting.net/teal/fly.jpg

My 91 s-10 flexplate cracked because of loose bellhousing and torque converter bolts. make sure there is no uneven pressure anywhere.

if you cant figure out what the problem is , i know certain companys make after market flywheels that bolt on to stock and are much thicker then stock , might give you just enuff more to make it so it doesnt happen again , or atleast put alot more time between the time it takes to break it

improper crankshaft balance can crack a flexplate quick. i would change your harmonic balancer.

oh yeah! forgot to tell you. i am not sure which way the 2.2 is balanced but find out from the dealer to see if the crank is balanced internally or externally. internally balanced cranks are balanced by taking weight off of the counterweights of the crankshaft. externally balanced cranks are balanced by the crank, harmonic balancer, and flexplate as one rotating assembly. just something to keep in mind.