Cylinder head removal

[Jared T.]

Hello, new to the forum. I just acquired a 2004 liberty 4x4 with a blown head gasket. I was reading somewhere that you can use a wedge tool to use on the timing chain instead of taking the timing cover off. Does anybody know if this is true or not?

 

[Lancer]

Diesel or petrol? If diesel, then there isn't a timing chain, its a belt. If you've only just got the vehicle, check that its been changed - should be every 100k miles OR every 5 years, whichever comes up first.

If there is no documentation to show its been changed, assume it hasn't been and do that. You can get the kit from idparts.

I don't know anything about the petrol engine in the KJ (in truth, I don't know much about the diesel either except that I've owned one for 9 years!)

 

[Conundrum2006]

I Just pulled the heads off a 3.7 motor to check if they were blown. Turned out to be death by gunk. (Thanks previous owner!)

From what I saw in disassembly I don't believe the wedge tool will work well. I used a wedge tool changing the cam phaser on a 5.4 ford, I'm familiar with how it works, I just don't think it will help much in the 3.7 V6.

If you have a 3.7 you can look at the pictures of my disassembly to see what you are facing. HERE http://www.jeepkj.com/forum/f196/3-7-oil-crud-probelm-59229/index15.html
The first few pictures show the timing cover off and how involved all the gears and guides are. Some of my pictures didn't come out, but you can get an idea of whats there.
If you're working on a 3.7 I can get specific pictures when I get home tonight if there is something you'd like to look at so you'll know what disassembly will be like.


To get the Cylinderhead off aside from the 8 main 15mm bolts under the valve cover you'd expect you have to get two small 10mm bolts inside the front part of the housing, to get to them you have to remove the timing guides which you really need the timing cover off to get to correctly. There is also a hydraulic tensioner for the timing chain you need to get to as well.

But to get the timing cover off you'll need two special tools, well three. First is a tool to get the bolt off the harmonic balance, might be a able to cheat on this, I as able to get mine off without it because the motor was pulled. The next tool is a three prong gear puller to pull the balancer since it does not have the standard bolts holes for a puller to attach to like older jeeps, my standard craftsman gear puller really didn't have the reach to puller it in one go again I was able to cheat because the motor was sitting in my garage.

The next probably more useful is a tool to lock the all the timing in place so you can take it apart. I don't have the part number for these tool but can find them if it'd help. I didn't bother with this tool because if the motor is rebuilt it's going to have to be pulled a part, cleaned and done from scratch.

I'm no expert so somebody may be able to tell you better, just from what I saw I don't think it'll work with just a wedge tool. It would be so much simpler if it could be used.

For the 3.7 v6 depending on the cost you're looking at it might be better to swap the motor out. Rebuilt Cylinderheads were pretty pricey when i priced them out a few months ago.

BTW IMO this is a doable job for most back yard mechanics it is just more involved than most motors.

 

[Conundrum2006]

Did a quick search, if you're working on a 3.7 it does not look like a wedge tool alone will work.
Link to a thread here: http://www.jeepkj.com/forum/f196/remove-head-without-removing-timing-cover-58576/

From just answer.com (follow this link for more info including disassembly instructions.): 2002 jeep liberty limited: a cam chain tennsioner wedge..timing chain

Hello and welcome to just answer. I am sorry but you have to remove the timing cover to do this and a chain tensioner wedge will not work on this engine. One of the guys in my shop tried that and he ended up pulling the timing cover anyway. It would be nice if you could use a wedge, but not on this engine or tyhe 4.7 V8.

EDIT: I see a few people have said they did the job with a wedge tool on a 4.7 v8, essentially the same motor as 3.7 except for 2 cylinders. Might be possible after all.

 

[Jared T.]

It the 3.7 engine

 

[Conundrum2006]

It the 3.7 engine

Personally I'd pull the timing cover, I'd bet you will find broken prices of timing guides.
TwoBobsKJ posted this FSM link in another thread.

Here is a link to the Factory Service Manual section on cylinder head removal and installation

However.
The people who did this (without pulling timing cover)successfully on a 4.7 v8 said the put a zip tie around the timing chain to pull it back up once it falls into the motor. There is marking the timing and the tool to hold the camshaft as you break the bolt free in the cam gear. They recommend turning the engine by hand to make sure the timing is lined up before trying to start it.

OEM Tool part numbers: (you might be able to find these cheaper through non oem tool makers.) IMO some of them can be substituted for other tools, like vise-grips and other harmonic balancer remover and installers.

Tools without pulling timing cover:
MILLER TOOL 8379 Timing Wedge.
Camshaft Holder Wrench Tool Miller Tools 8428 (8428A)

Tools for pulling timing cover:
MILLER TOOL 8513A CRANKSHAFT INSERT FOR 3.7L
Miller Tool 1026 Three Jaw Puller
Miller Tool 8429 Timing Chain Holding Fixture
Miller Tool Special Tool 8512

Honestly someone who has done this job in the car can answer these questions better.

Hope this helps.

 

[ltd02]

I have done an HG replacement and you have to pull the timing cover to pull the heads. Upper guides are up in there and you really have to get chains out of the way. No way to reset the tensioners if they relax too. The only thing the wedge will do for you is secure the chain to the guides if you are swapping the cam or cam sprocket. Check the picture in post 4 of the thread Conundrum2006 posted above: http://www.jeepkj.com/forum/f196/remove-head-without-removing-timing-cover-58576/#post665526

You can see how the guides are up in the heads. They actually attach to them up in there. Here's another good thread with some very good info especially from rbtconsultants:

DIY Head Gasket Replacement 2002 KJ 3.7L - JeepForum.com

 

[jharrisliberty]

Due to the fact that I am about to change my head gaskets this weekend I was doing a lot of research on how I was going to be able to do this. The best thing that you can do to really get an idea is take a good look at the FSM which is in a link up above. Not only does it tell you everything you are going to need to take off to change them, but also the specialty tools you will need and torque specs to put it all back together. If you need any pictures of this I could get them for you when I am working on mine this weekend.

 

[Conundrum2006]

BTW there is a hex head bolt on the passenger side head holding on of the guides, I think it is a 5mm of all the frustrating things is was one of the few tools I didn't have on hand. But I was able to loosen it form the other end and disengage the hydraulic lifter. If it had been in the car I doubt there would be enough room to lift it out. IMO the guys who say they did this job without removing the timing cover were working on Trucks with bigger engine bays and clearance.

Here is a pic of the hex bolt thingy you'll need a tool for. At least on the 2005-06 engine. The other weird thing on the same side is you have to remove the big bolt to access the other guide rail bolt. It's the rusty looking bolt in front of the second picture.

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[Jared T.]

Thank you guys for the input, im just gonna pull the timing cover and check everything while its off. Does anyone know how long such a job like this would take. And i found this information about the 3.7l engine hope this helps.
https://s3.amazonaws.com/iwantajeep/wp-content/uploads/2013/04/09-enging-37l1.pdf

 

[jharrisliberty]

I was told by the mechanic that took a look at it for me that it would take a good weekend to get it finished. I will say that this was with me and a friend that are both mechanically inclined working on this. He said that if I were to do it by myself that it could take about two weekends. This is all just speculation though. I will know for sure here soon though.