Okay, I hydrolocked one of my cylinders, and broke a piston rod. I was most fortunate to have it break outside of the cylinder so the wall is fine. I just bought the new piston/rod and oil-pan/gasket. (mopar i hate you). I am ready to install them but I do not know the best way to get to it. I do not want to mess with the timing too much, and I would like to do this myself. My mom and I are doing this as a project together and we both think it would be easier to r disconnect all of the rods from the crankshaft, and remove it, then pull the old piston out and put the new one it. There is NOTHING on the internet on how to properly remove a crankshaft from the engine out of a JK and I want to do this right, not halfass. So if anyone knows the best way to do this/ has any ideas of the easiest way to do this. Please let me know : )

thanks in advance.

 

IMO I would tear it down and inspect the damage before I went ordering parts. Do you have any experience in rebuilding motors??

 

Depending on how the engine is made and which rod and pistola it is...sometimes you can do the job from the bottom. I've done it once or twice before. You have to be REAL lucky, though. Since the Jeep is so damn new though, I'll be damned if I'd do it any other way but the RIGHT way. Just pull the whole thing and tear it down.

 

You will not be able to remove the crankshaft from the engine unless you remove it from the vehicle. You have the flywheel, front cover, damper, timing change and pulleys to remove the crankshaft.
You really need to inspect the engine good and make sure none of the other rods are bent. Being a mechanic for the last 20 years, I have yet to pull a piston out from the bottom of the engine. I am willing to bet you will have to remove the intake and cylinder head to remove it. I am also betting that the cylinder head gasket is damaged do to hydrolocking the engine.
You really should consult a repair shop or look for a Mopar shop manual for this particular engine to do it right. You will also need all of the torque specifications. If you put it together wrong it will self destruct.
And I will repeat. You should consult a good repair shop and just eat the cost. You may be better off in the long run.

 

i did tear it down, and I found a mopar parts catalog for my engine and ordered everything i need, so thats not my concern. I'm just unsure if i should continue going from the bottom and pulling the crankshaft, or if i should remove the manifolds and valves and go from the top.

 

thank you, that is something i will definitely check as well.

 

Like an earlier post states. There is absolutely no way to go from the bottom and pull the crankshaft. Almost all internals in and on the engine are connected to the crankshaft in one way or another. It would be more time efficient to pull the engine, inspect all parts, order parts as needed or another engine as needed, and then begin the process of rebuilding. If you don't have experiece in rebuilding an engine, I would recommend you study all reference material before diving in. It's not really difficult, but it only takes a little mistake to undo many many many hours of hard work. I've been there, and I am sure that many others have been there. Additionally, there is someone in the "for sale" posts selling a 3.8, might want to check it out. Good luck.

 

keep us posted on how this goes, I think you really need a service manual at the bare minimum, good luck anyway.

 

okay well today was 2nd to last day of assembly. tomorrow I am running to mopar to get the bolt i need for the intake manifold gasket.

I am surprised at this tear down. Going from the assembled engine down to being able to stick my hand through the cylinder and touch the crankshaft. And putting it all back together. Without a book, without anything but a general knowledge of parts.
I have learned 2 things, no snorkel = no water. And I can be more confidant next time i tear apart my engine b/c I know where everything goes. Some of my friends and family say it was pretty crazy and redneck of me to try to break into my engine without any instructions, make repairs, and put it back together; I just say, its a jeep thing.

 

What did you use for torque specs if the bottom end is not properrly tight the rods will come apart.

I want you to have it together right.