Flexplate Crack - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums

Welcome to LS1LT1.com/LS3forums.com - please click here to register...

LinkBack Thread Tools
post #1 of 2 (permalink) Old 12-01-2012, 08:12 PM Thread Starter
Regular Member
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
Green94Maro is offline  
Sponsored Links
post #2 of 2 (permalink) Old 12-03-2012, 06:54 PM
Regular Member
Join Date: Mar 2010
Location: Knoxville TN
Posts: 125
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.
kwacasey is offline  
Sponsored Links


Quick Reply

Register Now

In order to be able to post messages on the LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome