Flywheel keeps cracking

Hi there,

You may have a bent crankshaft, it may only be out a few thousands of an inch but this can cause real problems, check the run out on the mounting boss at the end of the drive plate, also check transmission alignment.

Mark (mhpautos)

Hi,

When it comes to the flex plate/flywheel cracking, any misalignment can cause it to happen. However, a single flex plate to break in the life of the vehicle can happen, but if it continues, like you experience, just replacing the part won't fix the problem.

Oftentimes, people will try using a heavy-duty replacement part, but that isn't a fix. Most times, the problem will be transferred to the transmission and cause issues within the front pump along with other bearings within the transmission.

Since this has been a reoccurring issue, excessive crankshaft flange run-out or end play is likely the cause. In most cases, this can occur in worn engines or engines that have been poorly rebuilt. On the other hand, if at any time the transmission was dropped or the torque converter was dropped, it can cause a misalignment.

If you look at the attached pic (number 1) it shows how to test for flywheel runout using a dial indicator. The remaining pics, related to vibrations, are for testing for flexplace lateral runout and for issues with the torque converter itself.

Check these things and let me know if you have other questions.

Take care,

Joe

See pics below.