02-04 engine swap

[Cribbs74]

I have an 02 KJ with a bad transmission, but with a good engine . I also have an 04 KJ with a bad engine and a good transmission. While I am sure everything will bolt up just fine, my concern is the computer systems. I only have the title for the 04 so I plan on pulling the engine out of the 02 and stuffing it into the 04

Theoretically it should work fine, just not entirely sure.

 

[Billwill]

I doubt that there would be a problem as regards the PCM but you may have to swap over some tone rings for the timing.

I will leave it to the Gasser experts to climb in here but there are probably some hits in the How To section!

 

[tommudd]

I have an 02 KJ with a bad transmission, but with a good engine . I also have an 04 KJ with a bad engine and a good transmission. While I am sure everything will bolt up just fine, my concern is the computer systems. I only have the title for the 04 so I plan on pulling the engine out of the 02 and stuffing it into the 04

Theoretically it should work fine, just not entirely sure.

They changed transmissions
04 motors are a breed all their own
computers etc
lot more work than " stuffing " it in

 

[04Liberty]

They changed transmissions
04 motors are a breed all their own
computers etc
lot more work than " stuffing " it in

Yeah, but the physical engine itself shouldn't matter as long as it has the correct tone ring. Any harness/sensor differences can be mitigated by using the same year as the vehicle stuff.

 

[ltd02]

The 02 autos were all 45RFEs and won't bolt directly up to the 42RLE. Different size connection at the crank. IIRC the 42RLE TC mates to a crank that has a pilot bearing in the end. Not sure if it is as easy as driving a pilot bearing into the 02 crank. I think if you're going the other way the pilot bearing can be removed and a later motor will physically fit the 45RFE TC.

 

[JasonJ]

Where is the title to the 02? In my state, you can apply for a missing title for about $15.. two weeks later it's in your hand.

Which KJ is in better condition overall?

If it were me, and the 02 were in better shape, I'd use the long block from the 04 to rebuild the 02's engine, make it better, new timing chains, all gaskets, seals, and hoses.. retain the (debatable) better 45RFE transmission. If the 04 had more options than the 02, use it as a donor to move them to the 02.

I think tearing down and rebuilding the engines/swapping them, inclusive of messing around with crank and cam tone rings is a TON easier than mucking about with the two varying transmissions.

 

[Robtrod]

I have an 02 KJ with a bad transmission, but with a good engine . I also have an 04 KJ with a bad engine and a good transmission. While I am sure everything will bolt up just fine, my concern is the computer systems. I only have the title for the 04 so I plan on pulling the engine out of the 02 and stuffing it into the 04

Theoretically it should work fine, just not entirely sure.

Hello and good morning. My name is Robert , and I have the same issues but my 02 came from Illinois undercarriage is rusted out and excellent motor bad trans. My 04 no engine good Trans. Are they compatible wil they bolt up correctly? They were both given to me free can anybody help me out. Thanks

 

[tommudd]

Hello and good morning. My name is Robert , and I have the same issues but my 02 came from Illinois undercarriage is rusted out and excellent motor bad trans. My 04 no engine good Trans. Are they compatible wil they bolt up correctly? They were both given to me free can anybody help me out. Thanks

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