5.2 to 5.9 Swap
 

I have a 1996 with a three inch lift. I will have questions on that eventually but for now i am replacing a blown 5.2 with a 5.9 with 155k , warranty for 550. I have researched this a little and see that there is a torque converter controversy. The engine is out of a 1995 Dodge Ram 2500. I know about flashing the computer but do not know how or where to do it. I have read to use the torque converter from the 5.9 and read to not use it since it fits a different tranny, but from the posts i was reading it was unclear it was because of years or the engine size. But i have to know by tommorrow whether or not to buy a torque converter made for the 5.9.
I wrote this sorta hastily, i am leaving town and having a local mechanic do this swap for me, and want to make sure i have everything for him. The old 5.2 is still in it, so he has them accessories and attachments to use. Any advice will be helpful, it's a good mechanic but i'm not sure how familiar he is with jeep stuff. He's more into classic mopar.
On the rough country lift it appears the upper control arms are all factory , while the bottom control arms are the longer, tubuler aftermarket arms. Not sure if this is just a rough country kit or parts are missing, but it makes the driveshaft angle harder for sure.

It's the black one from my album. BTW i did not buy a roughcountry lift, i would have bought one form iron rock offroad if i had bought one. I can't get into my album to put the pic here in the post.

While i was out of town working, i paid a mechanic to install the 5.9 engine, it runs good and smooth but refuses to take gas if i floor it, I did not flash the computer because i don't know how, but just slow normal driving it does pretty good. The torque converter did not need changed, the flex plate was the only thing that needed changed, actually only because the junk yard mangled the old one on the 5.9. It is a direct swap using the 5.9 flex plate. It has somewhat of a vibration at times , possibly a front u joint at to hard an angle? Or just a u joint getting ready to need replaced.

Some wiring needed extended, some hoses needed extended and switched around, had to use the 5.2 exhaust manifolds, the sensors had to be switched out on the throttle body, and other miscelanios wiring/plug changes.

So now i need a muffler and tail pipe, it just has a cat with a broken piece of muffler on the end of it and it sounds great, but i don't like getting tickets or drawing attention, lol

I started working the bugs out of this jeep. First i have to say i lost a little trust in my mechanic, the fuel vent was packed solid with dirt, it looked like a mud daubers nest or something. I paid the mechanic to change the fuel tank, he did but i can't believe he didn't catch that. The tranny cooler lines were both left loose and leaked at the radiator, it doesn't seem to take fuel well or it is starving for fuel. The oil pressure guage is not working, the oil looks filthy already after he said he just changed it also. It actually looks brown. The tranny may even be slipping or it spins the tires way to easy, not sure yet, and i have a vibration in one of my U-joints i think. other than that it is still really cool, although i'm thinking of **** canning the rough country lift and just getting a 4" lift from iron rock offroad. I can use the rough country lift on my 4.0 jeep. I saw a tag on the transfer that says 249, i really wish i had the 242 transfer in it, but im not sure it would hold a v8 especially the 5.9 v8. It's only a 15 hp gain over the 5.2 and 30 ft lbs torque gain but its way more than a 4.0. I may try to rob the cat, muffler and tail pipe from the 97 4.0, it has a dynomax super turbo on it and a larger walker tail pipe. I have to take it off the 4.0 jeep anyway since it may be clogged up, i think the cat shattered and clogged the muffler. I love the sound of that 5.9 with the screwed up scabbed on cat and no muffler, it actually sounds good, not like a junker missing an exhaust, but i know it's to loud, lol

I couldn't even put gas in the jeep from a can let alone at a gas station without it belching gas out all over the place. I still haven't learned about flashing the computer yet either. I did unplug the fuel line from both sides of the external filter and let some gas backflow through it, and it seemed to help for a while, as far as the engine gettine fuel.

My drivers seat is stuck from moving forward or back, and the sunroof is wedged in place with some wood, it's supposed to be motorized, i haven't even started checking fuses yet.

So far i have no sterio either and it had the system that had the amp under the seat, so im not even sure yet if i can plug an aftermarket 50x4 channel sterio in its place without bypassing that amp. From what i understand them amps aren't really very powerful anyway, barely more than a normal sterio. I really want to do something about the air intake also, it has a high volume reusable filter already, but is not sealed up, and i want a little more flow without sacrificing getting cool air from outside the engine bay. Many of the aftermarket air intakes hurt performance since they pull in hot air. I would like to have a hood scoop also if i can find a decent affordable set up.

As far as the intake goes, look for the stock system, air box, ductwork, etc. The flat pad filter will pass 5 times the air the engine needs and it takes cold air from in front of the radiator. If the front piece is open, it will actually pressurize at speed.

You need to clean out that fuel tank vent. That's probably what's starving the engine. There is a rollover shutoff valve in the filler pipe that must be pushed open when fueling, especially from a can.

If you don't care about power seats, the seat rail system for an XJ bolts right onto your floorpan and your seat will bolt to the manual rail system.

For a muffler, I like the Flowmaster ones. They are a little pricey, but will last longer than your jeep will. You can use a standard tailpipe, just extend the front pipe. I like the Super 50 myself. It's got a nice rumble without being harsh or really loud.

The 242 will take the torque no problem. For info on changing it, go to jeepforum.com/forum/f13/transfer-case-swap-info-np249-np231-np242-685644/

For the stereo, you're on your own.

To update this, I had to drop the tank and clean the fuel pump assembly out, and clean the screen at the bottom. The vent tube had been packed solid with dirt before not letting me put gas in, the screen for the fuel pick up was also packed with small leaves, mud dobbers, and dirt. So I have back together, running pretty good now, I had bought a dynomax super turbo muffler, high flow eastern cat, and dynomax tail pipe. It sounds pretty good and not really loud at all. Now the next problem is the tranny is leaking really bad from where the rear output connects to the transfer case. I suspect it is just a seal needing replaced, but what could cause a seal to leak that bad? It leaks pretty fast, I hope the tranny is still good.
Oh, when I first got this jeep I started pulling it with a tow dolly, everything in neutral and the rear wheels would lock up after about 20 to 30 ft. that's when I first noticed the tranny leaking also, when it was tilted from the tow dolly. So I have to ask how does the full time transfer work? is it more of a limited slip that locks in when you spin? Or is it supposed to always be locked? I had to remove one of the drive shafts to tow it.

I'm still thinking about swapping to the transfer case from the 4.0 jeep, I just think the 2wd option, full time and the part time lock option is better. And could I have broke something when I tried to tow it before I removed the drive shaft? I'm not sure how good this tranny is since I haven't been able to ensure that it was full of fluid ever, it leaks out so fast it may never have the proper fluid it needs to work right. Also I have been hearing rumors of a fuel injector swap that can be done, from a ford focus or fusion, I haven't gotten the exact year or car yet, but does anyone know about this?

it looks like the transfer case I have is a 249, I will have to look closer I guess its not supposed to exist, lol.

Seriously? All of the V8 ZJs came with the 249 unless it was ordered with the 242 by the original purchaser. You didn't have to remove a driveshaft to tow it. That's what the neutral selection on the transfer case shifter is mostly for.

It sounds like your transmission output shaft seal is GONE or leaking badly. There is a drain hole on the bottom of the t/case mounting flange. If the rig has been sitting a long time, that seal could have dried out.

The 249 is constantly in 4wd and a viscous clutch allows slippage between the 2 axles whenever a speed change is needed for going around corners or other reasons.

The 242 is, in my opinion, the best t/case jeep ever used. Just don't expect an instant huge increase in fuel mileage because even though all the power is going to just the rear wheels, the front wheels are still turning those gears and shafts anyway. You'll need to change the t/case input shaft to match your transmission. I some cases, you can use the shaft from your 249.

I was referring to a tech write up that a guy on here did, but later I looked at Wikipedia, they have a more thorough write up. Yes I saw that the 249 does exist, actually it has 249 D on the tag. It describes the workings of the 249 a little different. I don't care so much about the fuel mileage as just not feeling very secure when driving on really slick surfaces and it seems like you can always feel it. I just don't like full time that much. It is also described as being the same strength as all the 240 series. And I did have the selector in neutral when I tried to tow it, the tranny and transfer were both in neutral and it would go about 20 - 30 ft and lock the rear tires.