4.0 SOHC rebuild questions

[Snal]

Hello everyone, I've got either a cracked head or a leaking, not quite blown, head gasket. I will be pulling the motor tranny combo when I do the work as I plan on also doing the timing chains while I'm in there and I figured the work space would be nice. I've never done work the intrusive before but I believe I've got a functioning understanding on how everything works I just need a few questions answered.

My first question is: when I pull everything out, I plan on draining all fluids then divorcing the trans from the block. When I do this, if I unbolt the torque converter from the flex plate and leave it in the trans all I will have to do when the work is done is bolt them back together and fill everything back up right? I'm not sure if when I drain the trans if any necessary fluids in the TC will be lost and I'm trying to avoid anything unnecessary.

Second question: where to buy heads if the current heads aren't good anymore. I've found a rebuilt set on ebay for just over $400 but other than that the only heads I can find are tom moranas stage 1-3 heads and supersix motorsports heads which are mostly over $1000. I'm trying to keep it as cheap as I can without cutting any corners.

I'm sure there will be more questions that I can't think of right now, most of which being small details when I actually get down into it. If there's a walkthrough I can't find please leave a link to it.

 

[adsm08]

You shouldn't lose anything from the T-case when draining the trans. They use the same type of fluid but are sealed from each other. If you have some left over after filling the trans it might be a good idea to drain and fill the t-case too.

Head issues on the 4.0 SOHC were uncommon, although they had head GASKET issues through about 02.

While you are in there I would replace the rear jack-shaft bolt. It is apparently a more common point of failure than is generally know. (Google 4.0 SOHC rear jakshaft bolt and you get a bunch of pics of broken ones) At least price that at the dealer, when I had to replace mine I got a new one at the dealer for less than eBay wanted for a used one.

I wouldn't mess with the heads from Morana or Super6. They are both good, but they are for performance builds. IIRC the stage 2 and 3 heads require different (thicker) head gaskets or other things start breaking.

Also, just in case you didn't know (you probably do) you need some special tools to get the cams timed properly after disturbing the timing chains.

 

[Snal]

I was looking into the morana or supersix heads because my motor is the last mainly stock piece and I'd like to have it catch up to the rest of it but I just don't know how much I'm willing to spend haha. I'll do my best to leave the torque converter in unless it's simple to take out and fill back up. Another question i have is reassembly, I'll have to move my cams over to the new heads I'm assuming and I may even upgrade the cam while I'm in there. How do I get a new cam in and set it up for correct timing? Are there marks on the sprockets to line up with something or is there's some sort of marker for me to follow/line up? If so then that's all but if there's not how do I know where to set it after it's back in the head and the head is on the block?

 

[gw33gp]

As adsm already indicated. You need special tools (fixture) to time the cams. They are not cheap but needed. I am surprised there are not used ones available from people that bought them for a one time use.

 

[adsm08]

No marks, no key ways, nothing good for timing. You HAVE to have the tools, and as stated, they are not cheap. Performance cams for the 4.0 usually require performance heads due to the interference engine issues.

Leave the converter in. If you unbolt it from the engine and leave it in the trans you still need to re-seat it by rocking it around and pushing in on it. When it is fully seated you will hear it rubbing on the pump bolts. Failure to do so will destroy the transmission pump.

 

[Snal]

I understand the need for the tools and I do plan on purchasing them but my understand in that these tools will lock everything in place while I replace the timing chain so the cam timing isn't changed. My question is when I get the new heads they won't come with cams so I will have to put my old cams, or new cams if I get them, into the replacement heads. How do I set up the timing at that point? I won't have anything to lock into place because the heads will be completely off of the motor and the cams will be replaced. When I put the new heads with new cams back on the block how do I know when the cams will be at the correct timing? Will the locking tool only work when they're in the correct position? I don't know if I'm wording my question incorrectly or if I'm missing something that may be deemed as obvious or common sense, I've never done this before so I'm trying to figure out everything before I dig into it