When I did mine I could see the crack without removing and torque converter bolts you just have to look really hard for a black hairline around the bolts. And thats a horrible mechanic. $300 to begin with is a high price I did mine when i was 19 changed the pump seal and torque converter too also left the transfer case and rear part of the front driveshaft attached and used bottle jacks and blocks of wood. and pushed the jeep back and forth. Lining back up took like two hours though it was bad. If it does have to be changed I'd make sure it gets a new pump seal.

 

Can I ask a question here? You guys keep saying flex plate but my thoughts are flywheel...are we on the same page or not? Also my aw4 made a god awful knock before I swapped it out, turns out the flywheel to crank bolts wore out the flywheel some and made a crack in the flywheel. Knock would sometimes go away under constant acceleration but never entirely. Just my 2¢. Also you should make a short video of it running so we can hear the sound

 

They are the same thing. They call them flex plate if it's an auto and flywheel if it's a manual. Pretty much all vehicles as far as i know

 

.

 

what was the outcome?

 

Run it to destruction then you'll find out what caused the knock. The connecting rod sticking thru the side of the block will pinpont the bad piston.