I just picked up an crazy clean 98 GC for my wife.Her lease is done soon and I couldnt pass this thing up.I do believe it has a rod or a main knock.(I got it cheap so I didnt mind the knock)My plan is to drop the oil pan this weekend and look into replacing the bearings with the motor(4.0) still in the jeep.Does anyone know of any write ups or other helpfull information on this subject.As always thanks for the support guys!!!

 

I did few times. Make sure not to mix the caps. I would recommend doing one at a time. If your crank have any ridges then you will have to "turn it" or replace. Loosen up the cap nuts and gently tap to get a little slack between cap and rod. I use small piece of plastic to push out the rod bearing.
If you were driving for some time with a knack then it is a good chance that your crank my be damage too. I would check the oil pump.
Main bearings goes bad due to overheat or poor oil pressure.

 

Im not sure how long the knock has been there.Iv only owned it a week or so.I will definitly check the crank for score marks.Worst case I replace the engine.I was prepared for that when I bought it.Thanks for the insight i greatly appreciate it.

 

if you are willing to replace engine from junk yard, then i would recommend rebuilding existing engine as the junk yard engine my not be in better shape. it will cost you few buck more, but you will have known good engine. that what i will do. i did not rebuilt jeep engine, so i do not know the cost, but could not be much different that any other engine. the most i paid for kit (rings,bearings,seals,gasket set) was about$500, but i had a shop with all needed equipment. buying from junk yard it is risky, but you mu get lucky.
have a fun.

 

Thanks for the insight truckr.Does anyone else have anything to ad???All help is appreciated!!Is there any write ups or other info on this??

 

Most rod knocks are caused for a reason... but neather the less.. if its a LOUD knock...dont waste time pulling oil pan.. pull motor.. rod will have to be resized at the very very least... and mostlikly crank turned or polished.. eather way... cant do with motor in... Doing a shade tree rod knock repair never last...

 

i agree with trucker. I would run this engine, get another block and head out of the JY and have that one rebuilt or do it yourself. If you wanted to you can make a cheap stroker even there are many write ups on how to make a 4.2 or a 4.5 with nothing but parts from other engines. And then one the engine reman is done just drop it in and sell the one with the knock to make a few pennies back! or rebuild it and stroke it and drop it in your jeep !

 

Hey guys thanks for the feed back!!The knock is not loud at all,which is the reason I concidered doing this.The repair itself is not terribly difficult and only about 100 dollars.Im prepaired for worst case.I am going to do it.Probly to see if i can.If it doesnt work i will rebuild/replace the engine.Again guys thanks for all the feedback.....Damon

 

Well.. get the parts and camera.. take it down and post some pics...
and go from there... ?

 

x2 on the pics. I want to see

 

Heres some pics of the cheap jeep.Probly wont be till later in the week,but i will try to get the pics and attempt a write up.Thanks.....