Cruiser posted;
"Also you haven't acknowledged a very good suggestion that this Jeep probably has loose torque converter to flexplate bolts. You, or someone else capable of doing this, need to check them or you'll be paying for a flexplate in the future. Not cheap."

Maybe they didn't properly torque the flex-plate bolts after the new install.

 

Check the flexplate to torque converter bolts. Takes 15 minutes and it's a coimmon failure. Shine a light up there and look for cracks in the flexplate, too..

 

Thanks dude, i'll check it tonight.

 

X2...but it all depends. I'd rule a few things out before completely condemning an engine. But I still wouldnt rule rod bearings out.

 

Agreed. When it's a bearing knocking there is usually too much damage already.

That's why people need to check the flexplate to torque converter bolts first thing. Not a step to be skipped as it is common for the bolts to loosen up.

 

WELL... checked the damn flexplate and the bolts were tight. Had a few people listen to it and they think it's either the rear main bearing or wrist pin.

...I need C4.

 

Did you look to see if the flexplate was cracked?

 

I'm sorry to hear that man. If its only got 50k on it maybe its still under warrentee?

 

Bummer. Sorry to hear that. You can still amuse us though, ether with the C4 or an audio/video clip of your noise "s".

BTW, (and I almost need to don riot gear to say this!) My 90 with 263K will stop knocking on straight wt Castrol 30 wt. Been that way for 10 years. I get away here in relatively warm Cali. by always giving it a minute on a cold 40* morning.

I tried Castrol 10-30 last summer because you can't get the 30w in the cheaper 5 QT jugs. Drained it out to use for bar oil when the Jeep started it's little knock again.

 

How does it only take 15 min don't u have to pull the trans back? I need to check mine I have a knock

 

There is a small inspection plate/cover on the bell housing facing the pan. Take a 7/16 / 11mm when you go under to look.

 

Ok cool but how do u turn the plate?

 

Use a 3/4" socket on the front crankshaft bolt. Turn it clockwise. Whe you see one of the four flesplate bolts show up down below, loosen it up, remove it, clean the threads, add LocTite to the threads and reinstall it. Tighten it up as tight as you can with a long box-end wrench. Repeat 3 more times.

 

Anyone know how long it takes to rebuild the 4.0? No choice but to shop it. And dread it...

 

Thanks in going to do that now