I have an 86 Chevy K10 with a 350 and 700R4 automatic trans that is cracking flexplates.

originally they were cracking in 200 mile intervals I had a new torque converter installed and had the trans rebuilt. this flexplate has lasted just shy of 6,000 miles and just cracked again.

the engine runs smooth at idle and throughout speeds.

any ideas or suggestions would be greatly appreciated!

Thanks Mike

 

Are they cracking around the bolts????? This is a common problem and it sounds like it is an installation problem ie not getting the bolts torqued correctly or you are getting a run of bad ones....try spending the extra on a performance flywheel.

 

yes they are cracking around the crank bolts. i will spend the extra for the performance plate. also the current one is not a weighted balanced plate could that have been part of the problem?

 

I have seen that happen when you take a stock LM7(5.3 GenIII) out and put a LS1 in without changing the spacer between the flywheel and crank. I could be wrong though.