I just picked this jeep up, 88 cherokee 4.0 4x4... and it likes to knock. lol. I had a guy from the auto hobby shop here on the air force base look it.... he took a stethoscope and poked around.. he said sounds like its coming from the oil pan and that it is rod bearings, they aren't certified mechanics btw. I still think it may be the mains and or connector rod bearings. but I did an oil change with 10x40 and a 8cyl can of restore... to quiet the knock down so i would know. didnt stop the knock, maybe it kind of got quieter? but not really... so i took off the inspection metal and checked the torque converter. tried tightening the bolts and they seemed tight, only thing that happened was it turn the torque converter. Im guessing one of the bolts might have tightened a little.... because now the knocking is there whenever im in park or reverse... when i put in drive its quiet. took it down the road and u can still kinda here it while actually driving if the rpm are under 1k. i got under it again to listen closely with my ear and it definitely sounds louder by the torque converter than by the oil pan... granted its loud in general down there but hurts my ear by the flexplate... now im pretty sure its a cracked flexplate.... should i replace this myself or take it down to a shop. cant seem to find a write up on someone changing one out....

 

its quicker to have some on do it but it can be done at home

 

you should be able to see if the flex plate is cracked just by rotating it and looking at it yourself. Just disconnect the battery so you don't accidentally start your xj

 

lol cant see it up close though... ive read about a few that didnt notice it until it was pulled. still cant find a write up...

 

you can unbolt it from the trans and push convertor back and start motor to make sure the motor is no knocking

 

i read about this but i cant really picture it.....just unbolt the flexplate?

 

yep three bolts and push the convertr bac a little and start it dont let it run long

 

isnt it four bolts? also if i push iit back.... how do i bolt it back up?

 

three or four and the convertor can be pushed pretty easy a screw driver can move it

 

how do i get it back forward to bolt it up, also Ive never had to manual turn the motor... i did it early with the wrench on the flex plate bolt to get to the next bolt.. how do i do it with this screwdriver method...

 

i think you found this but hey...
https://www.cherokeeforum.com/f2/cra...-64080/index2/

I have also done this(on toyota's). just unbolt the 4 bolts the go threw the flex plate push a finger threw the flex plate and shimmy the converter back a bit. it should fall back just a little, enough not to touch. once it moves back turn it by hand and make sure its not dragging on the flex plate. once its not, fire it up and see if its gone. i wouldnt rev it to much but make sure its there or gone. then turn the flex plate (by the crank pully bolt) to where you can see the bolt hole threw the access, turn the converter and re-align the bolt holes and stick a bolt in it and start it by hand. it will suck the converter back into the right location. get it almost all the way in but not tight. then turn the motor over and get all 4 started and ALMOST tight but loose enough to where it can move just a little to make it easy to line them all up. then go and tighten them all 1 by 1. good luck.

 

so i went out to check it out, couldn't loosen the bolts with the wrench i have here at the house or id strip my wrench ha. since its night now i was able to see with a flash light a hairline scratch.... where there prob shouldn't be a scratch.



the yellow arrow shows where the scratch goes around... the yellow line shows what that scratch does at other points around the connector piece. It's not a perfect round scratch. its comes away and back to the round connector... i cant tell if its all the way through the flex-plate... so i think this is my crack... i ran a small screwdriver across it.. easily felt grove... sorry u cant see the actual crack, its up there and lighting isn't right. looks like it goes completely around... so that could be bad. going to see about getting it fixed asap.

anyways... here is a pic of the lovely Jeep that knocks.

 

so today I went back to tighten the tc bolts again. I was successful this time cause I changed the wrench angle and used another wrench to push up on it... It made it a tad bit quieter... Didn't work cause its cracked... Also with engine running I pulled number six plug wire and shocked myself lol. I just wanted to see if rods bearings were knocking... Knocking didn't stop. Getting flex plate replaced tomorrow..

 

Well I picked her up yesterday and she is just running amazing... Costed 500 because I used their part, but they warranty it... So if I have a wrapped crank and it breaks again I'm good four months down the road