wj 4.7 to 4.0 swap

[Curtis_H]

Hey all, im looking for a wj and im finding a few for a good price with a bad 4.7. Im just wondering how much would be involved in swapping to a 4.0? I know the wiring and computer, mounts, exhaust, and possibly the transmission, but are there any major hurdles? Please, don't tell me it's a stupid idea unless you have info.....I know its a big project, im just looking for some insight from someone more familiar with the WJ....

 

[shortxjdoug]

the entire thing is a major hurdle.. entire wiring harness, engine, transmission, mounts, computers, interfacing with the body control module... why not just put a used 4.7 back in it, it would be both easier and cheaper to do.

 

[Curtis_H]

I am REALLY not trying to be rude here so please no offense.........I completely understand that it would be far far easier to just install a 4.7 back into it. I know that the swap will take alot of work, BUT as I am looking into these I am finding ALOT of them with bad 4.7s. SO, I don't want a 4.7, I want a 4.0. Before I go spending alot of money on one that already has a good 4.0 i just want to know how much will need to be changed to swap in the 4.0 in place of a 4.7. Are the frames (unibodys, frame substitutes, whatever you know what i mean lol) the same? tranny?
Any of the wiring useable or does it all need to be changed? Fuel pump? Fuel tank? Radiators? anything else?? Thanks guys, I know I'm being beligerent here but Im just trying to do a little research before I buy.

 

[FlexdXJ]

You know why those 4.7's are bad? You are looking at Vehicles that have not been taken care of! The 4.7 is a good motor. My stepmom's durango had one. It ran great and the durango would get up and go and they are heavier than the WJ! Then again it was taken care of!

 

[DesertRunner]

i bought my wife a 04 wj limited with the 4.7 that thing has way more power than my 97 4.0 and geta 16mpg mixed my cherokee gets 17 mixed... i wouldnt trade that 4.7 for a 4.0 if i was paid to!