Finally diff in 3.7’s (well at least to 05)

Finally diff in 3.7’s (well at least to 05)

Remember I only covered up to 05

Need an engine for your 02-03 well now here it is:
1. All bare blocks 02-05 are the same no change will fit both auto trannys.
2. All bare heads Left and right side are the same 02-05
3. All head gaskets, and timing chains and guides are the same

What’s not the same…..
1. Crankshaft same 02-03 changed in 04-05. this is what prevented
the 02-03 ****** from fitting on 04-05 3.7 engine
2. Came gears 02-03 are the same changed to electro magnetic wheel on
the 04-05
3. Crankshaft gear same 02-03 changed 04-05.

So now if you want a 04-05 engine in your 02-03 here is what you do…..
1. Strip off the 04-05 to a plain long block (no sensors, manifolds ect)
2. Purchase a 02-03 crankshaft kit comes with all new bearings about $280
3. Now replace the cam gears from the 02-03 on to the 04-05
4. Put in the crank kit. You can still use all the timing chains and guides
5. Now switch over all your manifolds Ex, In, Injec, all sensors
don’t forget to switch over the crank pos. sensor they are diff.
6. Install the engine.

did it work

strong1 said:

6. Install the engine.

Click to expand...

Great summary and congratulations!

I have been out of town for some time now. so sorry i had not posted. YES! it works i have not had any problems so far. Its not as had as it sounds your prob. looking at a few extra hours of the engine on the engine stand. Just keep track of all the caps from the rods and put them on the same way you took them off and torque everything down to spec.
Thanks

sticky this!

It's a sticky now with stars too.

Dave

WHat rods do you keep the 02 or the 05s?? Which manifolds also, I bought a running 05 to replace my 02.

Does anyone know why or better phrased, how they are different?? Cant the 04-05crank be milled or can the mounting plate or that starter ing or whatever be modified or what?? Is there a pilot bearing or something going on?

Basically what is the exact reason why it doesnt work?? Do I need to put them side by side to see the difference myself, I am not trying to sound like a smart ashe?? There something I dont understand about the differences in them??

I have an 07 motor we are putting in an 03 Jeep Liberty.

1. Change the tone ring from crankshaft.
2. Change the camshaft sheetmetal ring on right head to the older style.
3. Block off egr valve
4. Use the older intake and exhausts.
5. Remove the bearing inside the rear of crankshaft( looks like a pilot bearing) the newer trans had a much smaller pilot thatn the old one.
6. Reinstall

Worked great and with little trouble. Drives like a brand new vehicle.

Trans mounting

importandy said:

Does anyone know why or better phrased, how they are different?? Cant the 04-05crank be milled or can the mounting plate or that starter ing or whatever be modified or what?? Is there a pilot bearing or something going on?

Click to expand...

There is a bearing in the back of the crankshaft that must be removed for the tranmission snout to fit. It is easily removed and then it worked perfectly.

Used the original 2003 flywheel and transmission and the new 2007 motor and crankshaft with the bearing removed.

Driving it now. No problems with over 300 miles since the engine swap.

Surprised nobody has mentioned the differences in the engine controllers either.

The real reason why 04 and up won't run into an 02 and 03 is because these engines are set up for the NGC controller, and not the older JTEC controller. Swapping these parts solves the problem, as you are basically setting up the newer engine to run with the JTEC controller.

Now the question is, does anyone know when the JTEC/NGC switch happened? Did it happen strictly with the 2004 model year *or* part-way through the 2003 model year? (I have a suspicion this is really what happened...)

JTEC (Jeep/Truck Engine Controller) has 3 electrical connections.
NGC (Next Generation Controller) has 4 electrical connections, like seen here:

Also, the NGC controls the engine and transmission. The JTEC controls only the engine and the transmission requires a separate controller... unless you have a Jeep with the W5A580, which has its own transmission controller.