Cracked Flexplate?

[SwampSurvivor]

This is my 2000 Jeep Cherokee 4.0L / Auto. It's had a bit of a bottom end knock for a few years now - always figured it was a bad case of piston slap. May still be, who knows!

Anyway, this weekend I pulled the oil pan off to change the oil pan gasket and rear main seal.

Had to take the flexplate cover off to get the rearmost pan bolts out.

I believe this is a crack around the hub / flange part that bolts to the engine. This is where they crack. If you look above the torque converter bolt in the picture, the crack appears there. The metal also looks clean like it is rubbing or moving around.

Pic

Video
https://www.youtube.com/watch?v=KYuny4UQM44

https://www.youtube.com/watch?v=Emcfq3BnlzY

 

[Chris142]

Pretty common. The flex plate flexes and eventually cracks

 

[SwampSurvivor]

Does it look like it's cracked? To my untrained eye, it does appear to have cracked.

 

[UNC017]

Hard to tell for sure, but it does look suspicious. That, combined with a "bottom end" type knock would be enough for me to swap the flex plate. A broken flex plate sounds very, very much like a deep bottom-end knock.

 

[cptbarkey]

You could try loosening the bolts to confirm, but be ready for the flex plate to break and then pull the engine.

 

[asand1]

Here yah go

 

[SwampSurvivor]

Originally Posted By: 440Magnum
Hard to tell for sure, but it does look suspicious. That, combined with a "bottom end" type knock would be enough for me to swap the flex plate. A broken flex plate sounds very, very much like a deep bottom-end knock.



I pulled the cover off before, but only to check the bolts from the torque converter. Never looked at anything else. I think I will be calling the mechanic and getting it in!

I can handle replacing the RMS and oil pan gasket, even the head when that cracks but I don't feel like removing the transmission.


Originally Posted By: cptbarkey
You could try loosening the bolts to confirm, but be ready for the flex plate to break and then pull the engine.


It's probably easier to disconnect it from the torque converter and drop the transmission out, then change the flexplate to the engine.