yes the flex made by gm are not very good either i went through 3 of them untill i got one that was not cracked.all bought from a top chevy dealer.could the parts people putting bad parts back in the system? i worked for a big gmc dealer in northern va. and they had some mach.spin main and rod bearings using a screw driver and hammer.so the customer could get a new engine under warrenty because the current engine was not powerfull enough.no wonder gm went under.dishonest dealers and bad products