Project LookOwt: Saving a piece of 3.0 history

[Ondonti]

I found out last week that even the 1996 a670 has case upgrades over the 1995 3.0 a670 and then Vigo mentioned to me the transfer gear retainers it also has. I went to get a backup transmission for my wife's car and picked up 1994 and 1996 3 speeds.

[Force Fed Mopar]

About to start working on this again. Got it at my parents house as they have a much nicer shop Got it jacked up on stands, got the wheels off, got the trans side cover off and draining. Got the engine stand and tools there ready to go, just need the hoist and I can jerk the drivetrain out, pull the trans off and rebuild it, and put the engine on the stand and tear the heads off so I can spec everything out and know exactly what my compression ratio and quench clearance is. Should be interesting to get some real numbers off this 3.2 stroker kit it's supposed to have.

Side note, I found that vacuum leak that was bugging me, apparently you should not reuse even metal intake gaskets It is leaking between the intake and the head. Good thing is that the injectors are sealing right, so I shouldn't have to remove the nitrous spider again lol. That is a real PITA, let me tell you...

[Ondonti]

About to start working on this again. Got it at my parents house as they have a much nicer shop Got it jacked up on stands, got the wheels off, got the trans side cover off and draining. Got the engine stand and tools there ready to go, just need the hoist and I can jerk the drivetrain out, pull the trans off and rebuild it, and put the engine on the stand and tear the heads off so I can spec everything out and know exactly what my compression ratio and quench clearance is. Should be interesting to get some real numbers off this 3.2 stroker kit it's supposed to have.

Side note, I found that vacuum leak that was bugging me, apparently you should not reuse even metal intake gaskets It is leaking between the intake and the head. Good thing is that the injectors are sealing right, so I shouldn't have to remove the nitrous spider again lol. That is a real PITA, let me tell you...

The new style Felpro intake gaskets have proven the ability to be removed and reinstalled countless times for me as long as they don't get damaged. I surely have the record for that and one of my sets dates back to 2002 and that one has done a lot of passing around and racing. Kept using it because I had matched it to the intake ports.

When I first started working on 3.0's I had a lot of headaches when I reused the OEM MLS intake manifold gaskets. To date I mostly still use MLS style exhaust manifold gaskets but that is not something I have been careful diagnosing leaks on. The exhaust crossover MLS gaskets work even when they fall apart.

[Reaper1]

I'm glad to hear you are getting to work on it again! I am SO interested in the guts of that engine. When I first got it I had the intention of resealing the engine and I was going to take it all the way down and do all the measurements etc.

[Vigo]

Glad to see this moving along again. Let us know if you find anything interesting in the transmission. Are you doing the trans yourself?

[Force Fed Mopar]

Yeah I think I am going to try my hand at it. No bands or anything to set really so shouldn't be hard at all.

[OG_SRT4]

Pics and write up if you do it please.

[Force Fed Mopar]

Will do. I got an '03 41TE core to get the good guts out of (planetaries, shafts etc), and I'm going to try and get Alto Red or similar clutches. Probably do some line pressure mods. I know Racerstev drilled the valve body in spots to increase flow but he never posted how big. I do know he felt he went to big at one point. I'll probably have to buy the ATSG 41TE/604 manual to find out where to drill also, unless someone has one I can borrow

[Vigo]

One of the things about drilling your way to faster shifts with the 604 is that BECAUSE it has no bands, any time one clutch pack applies another one has to release to avoid flaring/binding and that timing has to be extremely precise. You can make something apply faster by increasing fluid pressure or enlarging orifices, but you can't really speed up the release time very practically because a lot of it comes down to the stiffness of the return springs for each clutch piston.

You might check and see if there is a hi-po clutch/seal kit for a 42rle for a Jeep. They might use the exact same clutches as the older 604 since it's basically a 604 in a rwd case.

I have the 604 atsg book in a desktop computer that's not set up right now. I've been meaning to hook it up in the garage, so if i do that anytime soon i'll find a way to send you the pdf of it.

[Force Fed Mopar]

One of the things about drilling your way to faster shifts with the 604 is that BECAUSE it has no bands, any time one clutch pack applies another one has to release to avoid flaring/binding and that timing has to be extremely precise. You can make something apply faster by increasing fluid pressure or enlarging orifices, but you can't really speed up the release time very practically because a lot of it comes down the return springs for each clutch piston.

You might check and see if there is a hi-po clutch/seal kit for a 42rle for a Jeep. They might use the exact same clutches as the older 604 since it's basically a 604 in a rwd case.

I have the 604 atsg book in a desktop computer that's not set up right now. I've been meaning to hook it up in the garage, so if i do that anytime soon i'll find a way to send you the pdf of it.

You read my mind lol, I was just thinking it'd be great if someone had it on their computer that could e-mail it to me

From what I could tell, the 42le is a 604 w/ a different diff setup. Supposedly the diff is what gives it it's higher torque rating (2 instead of 1), but not positive on that.

[Force Fed Mopar]

I found the ATSG manual downloads, right here:

http://www.turbo-mopar.com/forums/sh...uot&highlight=

So I have the manual now, just have to sit down and study it.

May have the trans out today.

[135sohc]

You read my mind lol, I was just thinking it'd be great if someone had it on their computer that could e-mail it to me

From what I could tell, the 42le is a 604 w/ a different diff setup. Supposedly the diff is what gives it it's higher torque rating (2 instead of 1), but not positive on that.

The 42LE is the LH car transmission, its a FWD transmission oriented like a RWD, its got a built in hypoid type differential to turn the power 90* and drive the axles. The 42RLE (rearwheel drive) is the same thing but instead of the sprockets, transfer chain and differential to re-route the power to the front wheels it just goes straight out the back. The front section of a 42LE other than the oil pump stator support and input shaft both being longer is the same as a 41TE. The clutch assemblies and gear train parts are the same.

[Vigo]

The 42rle has been put through some real abuse in the JK Wrangler community. If there have been any useful developments in beefing the basic 604 guts, it would probably come from that. However, unlike my 604s and 606 i never had to rebuild the one 42rle i've owned and so i've had no personal experience to tell me that the guts ARE the same like they are with the 606/42le. HOPEFULLY they are.

[Force Fed Mopar]

Well I didn't get the trans out today, got a tweaked muscle in my back or something so didn't feel like pushing it. I did however go to the shop after work tonight and get my core tore most of the way down. I think it's newer than '03, valve body has VLP cast on it which would seem to indicate it has variable line pressure. I don't think that came out until '05? I took a bunch of pics of it.

[Vigo]

My 06 Magnum had it so i think your 05 guess is pretty close. The VLP thing could be cool if we had software to control it, but i think since we are at such an early stage of trying to figure out 604 control it's probably something we should ignore until more important things are figured out.

[Force Fed Mopar]

Yeah I wasn't trying to use it '06 was the first year for VLP I found out.

[Force Fed Mopar]

Drivetrain is out of the car. Pulled it in one piece out the top pretty easily. Headers are fairly well designed, only thing I had to take loose was the downpipe.

[Reaper1]

Very nice! One thing Rick told me when he sold me the car was that there probably should be an expansion joint around the 2-to-1 joint. It uses a standard Mistu 3000GT exhaust gasket, but he said he replaced many of them...most probably because of vibration and heat expansion/contraction. Just something I thought would be useful, if I hadn't mentioned it before.

[Force Fed Mopar]

Separated the engine and transmission today and got the engine tore down to the short block. Took a lot of pics, when I have a chance I'll get them uploaded.

Pistons look like some type of stock piston, but not 12v pistons. I think they might be stock DOHC pistons with a relief cut for the intake valve.

[Ondonti]

Separated the engine and transmission today and got the engine tore down to the short block. Took a lot of pics, when I have a chance I'll get them uploaded.

Pistons look like some type of stock piston, but not 12v pistons. I think they might be stock DOHC pistons with a relief cut for the intake valve.

So you are saying they are cast? I find that odd to add valve relief's since Mitsubishi ran their 10:1 12 valve Diamantes with no valve relief. I wonder who actually built this last shortblock. They could also be 12 valve diamante pistons
OR they could be larger diameter 6g74 10:1 pistons DOHC or 24v SOHC but I think there would be a rod length issue.
BTW, I really wonder about actual compression ratios on some of these motors with their various combustion chamber sizes and piston dishes. There are DOHC and SOHC 24 valve versions of the 6g74 so everything should be a little different.

Pictures of the rods too!