2.5L-4.0L Swap

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Apr 3, 2009 | 01:42 PM
  #1  
My '85 cherokee is running the 2.5L engine and i'm getting ready to put the 4.0L out of an '89 cherokee in it. I know it's going to be a PITA but if anybody has any suggestions or tips they would be appreciated.
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Apr 3, 2009 | 03:34 PM
  #2  
OK, take this with a grain of salt. Why are you willing to invest that much time and money into your cherokee? Couldn't you buy one with a 4.0L for about the same cost as the swap? Again, no harm in doing the swap just had to ask. I know where I live I can buy a running XJ around that year for under 500 bucks.
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Apr 3, 2009 | 04:31 PM
  #3  
I agree with the poster above but... what you will need is everything forward of the fire wal connected to the motor. That means frame mounts and wiring harness. It also means driveshaft, x-memeber, t-case linkage. Depending on what gauges you have it means them too. A buddy of mine did this swap. He was meticulous, and it took him almost 3 months, and a crap load of parts from my house and the Junkyard. He did this in a MJ, and I can almost justify it then, cause they are getting harder to find clean bodies.
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Apr 3, 2009 | 06:26 PM
  #4  
screw the 4.0L, throw in a 4cyl cummins diesel! that would be wicked
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Apr 3, 2009 | 07:27 PM
  #5  
Quote: OK, take this with a grain of salt. Why are you willing to invest that much time and money into your cherokee? Couldn't you buy one with a 4.0L for about the same cost as the swap? Again, no harm in doing the swap just had to ask. I know where I live I can buy a running XJ around that year for under 500 bucks.
Quote: I agree with the poster above but... what you will need is everything forward of the fire wal connected to the motor. That means frame mounts and wiring harness. It also means driveshaft, x-memeber, t-case linkage. Depending on what gauges you have it means them too. A buddy of mine did this swap. He was meticulous, and it took him almost 3 months, and a crap load of parts from my house and the Junkyard. He did this in a MJ, and I can almost justify it then, cause they are getting harder to find clean bodies.

Here's the reasoning and what I'm after:
  • This jeep has a lot of sentimental value to me. It was my great grandpas and he bought it new. He was always a fan of playin and really wanted to do the engine swap but was getting too old. When he passed it down to me he asked me to build it into a crawler and do the engine swap...so that's what I plan to do.
  • I just bought an '89 cherokee with the 4.0L but it's got the selec-trac system which I don't care for one bit. So my plan is to take the engine and tranny and I have a NP231 transfer case to go behind that when I get it in my jeep.
  • Do I need the entire wiring harness out of the '89? Do the engine mounts match up or are modifications going to need to be made? What is it that's going to cost me so much money? (So I can start to plan a budget) Will the fuel tank and pump out of the '89 bolt right into mine or are mods needed? Will the automatic tranny and the NP231 transfer case bolt up to my crossmember or are mods needed? Etc...
Any help would be greatly appreciated. This jeep means a lot to me so I want to get things done right if you know what I mean. If someone could even come up with a list of what I'm going to need to pull off of the '89 cherokee with the 4.0L to switch over to my '85 that would be awesome.

Thanx...
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Apr 3, 2009 | 09:57 PM
  #6  
Having a donor vehicle will be EXTREMELY helpful.
If you search around this forum, there are a few threads with info about what would be needed to swap a 4.0 into early XJ's that had 2.8 V6's...I would expect that a lot of the info would be relevant and helpful. You have a significant amount of work ahead of you, but it CAN be done.
Good luck!
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Apr 3, 2009 | 10:42 PM
  #7  
Its not all that hard,and given that you have the doner rig your way ahead of the game! you will need to swap out all of the wiring from the radiator to the dash and then some! you will also need to drill out the spot welds holding the left and right side radiator support panels, as these are needed for the 6 cylinder radiator as well as for the hood latching mech. I spent 3 1/2 weeks working on mine 6 to 12 hours daily to complete the swap, but i also swapped out all the wiring nose to tail as well as the entire interior. I say go for it !!!!!!! If you have any questions or problems please feel free to contact me!I will gladly do my best to help. J.C.
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Apr 4, 2009 | 11:18 AM
  #8  
Quote: Here's the reasoning and what I'm after:
  • This jeep has a lot of sentimental value to me. It was my great grandpas and he bought it new. He was always a fan of playin and really wanted to do the engine swap but was getting too old. When he passed it down to me he asked me to build it into a crawler and do the engine swap...so that's what I plan to do.
Thanx...

Thats a good reason. I would do it too. A good donor vehicle is a must as well as having a friend with a 4.0L so you can look at it and compare now and then when you get stumped on something.
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Apr 4, 2009 | 11:19 AM
  #9  
What about the engine mounts? Will they go hand in hand or do i need to pull the engine mounts and brackets from the frame of the 4.0?
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Apr 4, 2009 | 11:21 AM
  #10  
Quote: Its not all that hard,and given that you have the doner rig your way ahead of the game! you will need to swap out all of the wiring from the radiator to the dash and then some! you will also need to drill out the spot welds holding the left and right side radiator support panels, as these are needed for the 6 cylinder radiator as well as for the hood latching mech. I spent 3 1/2 weeks working on mine 6 to 12 hours daily to complete the swap, but i also swapped out all the wiring nose to tail as well as the entire interior. I say go for it !!!!!!! If you have any questions or problems please feel free to contact me!I will gladly do my best to help. J.C.

Thanx for the help!
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Apr 4, 2009 | 11:36 AM
  #11  
K so i was just reading around and there was one guy saying that the engine compartment is shorter in my '85 than in the '89. True? If so will the engine and radiator still fit?
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Apr 5, 2009 | 07:28 AM
  #12  
Quote: K so i was just reading around and there was one guy saying that the engine compartment is shorter in my '85 than in the '89. True? If so will the engine and radiator still fit?
That is what I have always been told. It is not a shorter compartment but the firewall is a different shape so you have to do some work on it. I understand the great grandpa handing it down. But you got a lotta work ahead of you. If you do you deffinetly need to keep us up to date. Good Luck.
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Apr 5, 2009 | 10:34 AM
  #13  
Fire wall
Quote: K so i was just reading around and there was one guy saying that the engine compartment is shorter in my '85 than in the '89. True? If so will the engine and radiator still fit?
there is no truth to there being any difference in the firewall! I have an 85, and put the engine, transmission, transfercase,etc. in from a 91. I went from a four speed to a five speed, and from an np 207 to an np 231-- the transfer case shift bracket was different in that it has a bracket that attached to the transmission tunnel and the linkage mounts between that bracket and a bracket on the transmission. easy to figure out as you only have to measure the holes on the donor to know where to drill the holes in your xj. This is where having a complete donor xj comes in very, very handy!!!!! As for the engine mounts i don't remember if i had to swap out the actual frame mounts since its been 4 years, but you will know as soon as you get both motors out! I would take a look at mine, but its at my best friends welding shop where i started my axle swap yesterday.
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Apr 5, 2009 | 10:49 AM
  #14  
Meant to tell you that the difference in length under hood is only because the 2.5 radiator is moved towards the engine with the brackets that you will be changing out to install the 4.0 radiator. There is all the room needed to install the 4.0, but like i said -You will have to drill out the spot welds on both xjs, that hold the left and right rad. support brackets. these brackets also hold your headlights, and the lower half of the hood latch system. You might be able do the job without doing the drilling, if you use old school drag racing style hood pins?!!!!! I'm getting ready to go work on my jeep and will look to see if hood pins will work as it will save you a lot of work!
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Apr 5, 2009 | 11:14 AM
  #15  
Quote: there is no truth to there being any difference in the firewall! I have an 85, and put the engine, transmission, transfercase,etc. in from a 91. I went from a four speed to a five speed, and from an np 207 to an np 231-- the transfer case shift bracket was different in that it has a bracket that attached to the transmission tunnel and the linkage mounts between that bracket and a bracket on the transmission. easy to figure out as you only have to measure the holes on the donor to know where to drill the holes in your xj. This is where having a complete donor xj comes in very, very handy!!!!! As for the engine mounts i don't remember if i had to swap out the actual frame mounts since its been 4 years, but you will know as soon as you get both motors out! I would take a look at mine, but its at my best friends welding shop where i started my axle swap yesterday.
Thanks for clearing that up. I never really wanted to believe it but I got some friends out here that said they were and I seen it a couple times on the forum. I didnt figure jeep would do something dumb like that. Thanks again.
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