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post #1 of 2 (permalink) Old 12-01-2012, 08:12 PM Thread Starter
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Green94Maro's Avatar
Join Date: Apr 2012
Location: Iowa
Posts: 126
Flexplate Crack

Hey guys, it's been awhile since I've been on here since my LT1 swap this summer. Car ran great after we got everything back together. Anyways, the other day I went to start it up after driving it the night before and there was a clanking noise that would come and go while idling in park. The noise was coming from the torque converter/flexplate area. First thing I checked was to make sure all 3 of the torque converter bolts were torqued down to 46 ft-lbs, which they all were. The next thing I decided to look for was a crack in the flywheel. While looking I found this little hairline looking crack, but I wasn't sure so I took a picture to get some more opinions. Is my flexplate cracked? Thanks guys.

1994 Camaro - 95' LT1 Swap: CC304, K&N CAI, Pacesetter LT's, Pacesetter ORY, Magnaflow Catback, AIR!, EGR!, A/C!, TB Bypass, Founder's LCA's, Panhard, Subframe Connectors and Strut Tower Brace. PCMforless Tune
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post #2 of 2 (permalink) Old 12-03-2012, 06:54 PM
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Join Date: Mar 2010
Location: Knoxville TN
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I really cannot see from the picture, I have had a similar problem on a car a few years back, in which the flex plate was cracked. The car would clank and sound like crap at idle, however at higher rpms the sound would go away.

When i pulled the flex plate i found that there were cracks around the bolt holes that attach the plate to the crank. The cracks looked fine but they were present on both sides of the plate. Based on the thickness of the plate i could not force the cracks open or anything like that.

I expect that cracks in other places would cause the same issues.

Hope that helps

1993 Camaro Z28 A4 (4L60 non-"E")
K&N CAI, BBK TB, Superior Perf. Shift reprogramming kit, Corvette Servo, NGK TR55IX plugs, Taylor Cable Thunder Volt 8.2mm wires, founders perf rear LCA & PHB.
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