Quote Originally Posted by REDCOMPG View Post
Lime green accessories causes broken flex plates



Seriously I'm curious as well seems like some guys have the issue and some don't
General Motors had problems with this on their 3.8L engines several years ago. The bolt pattern and dowel pins may be drilled improperly. When this occurs the vehicle is likely to have continued problems with flexplate breakage. A dial indicator may be used to check symmetrically designed engines. On non-symmetric engines, special jigs and complex measurements may be needed.
The more excessive the misalignment, the more frequent problems occur

Slight misalignment may only cause a single flexplate to break in the life of the vehicle. More severe misalignment can break a flexplate in 15,000 to 30,000 miles. Excessive crankshaft flange run-out or end plate can also cause flexplate cracking. This may occur in worn engines or engine that have been poorly rebuilt. An engine, transmission or torque converter that has been dropped may also have damage that will cause misalignment.
When a running engine ingest water or coolant, the crankshaft may be bent. Liquids will not compress and immense force is placed on the crankshaft and rods. This sometimes happens with a leaking intake manifold or driving on a flooded street. The bent crankshaft will have run-out at the flange and may have continued problems with flexplate cracking.
The same things that cause the flexplate to crack can also cause transmission problems. Damaged and leaking front seals and front transmission pumps are common symptoms.
When a flexplate cracks, it often produces a loud knocking noise as it rotates. The sound is very similar to a bad engine rod and is often misdiagnosed. Removing the bolts to the torque converter and sliding it back into the transmission will often reveal the real problem.
When a flexplate breaks, it is important to find the cause

Simply replacing the flexplate will result in recurrence. Trying to install a heavier duty flexplate will normally pass the problem to the transmission. Correcting the cause of the misalignment is the only repair that will give permanent results.