Dropping a 4.0 into and YJ 2.5 frame

[pianoguy]

Is this to much trouble than what its worth?

I know the motor mounts have to be moved. Other than that what else?
Wire harnes?

[jps4jeep]

mods to the frame will only be the motor mounts, yes the wiring harness will have to be swapped, as well as all the emissions equipment

[Twisty]

will the tranny work, or do you need a new tranny?

[pianoguy]

Ijust saw a few good deals on 93 YJ that have good frame and bodys but have 2.5. I know my motor and Trans are in good shape. I was thinking that insted of swapping every thing to another frame.

[rockdaleTJ]

I dontknow if you have the AX-5 trans in yours, but from what ive read about TJ's, putting a 4.0 in front of it is a big job.
Not worth it in my opinion.

[PatriotYJ]

get it.... your would reatain the 4:10 gears and you alraeady have the right drivshafts from your jeepso you dont have to make or buy those.
so the best thing to do i take evrything from the radiator back and put yours in, change the motor mounts and call it a winner.
i dont remember what year your jeep is but you may have to swap the speedo in order to keep it working.... early years had cable drive, and later went with electonic speedo. but none of that would be a huge deal because you have a complete donor jeep(yours)
if yours is an automatic now you may want to make it into a floor shifter in order to keep colums in place.


things that wouldn't work is the 4.0 in front of AX5(tranny that comes behind 2.5)
also the tcase from the 2.5 is a different spline count than the one behind the 4.0
the 2.5 radiator not the same as 4.0
also you'd need to retain the 4.0 ecm from the donor jeep.

Its definatly a long and involved project but very doable with the right tools, the question is wether its worth it. is your frame and body that much worse than the one your thinking of putting the motor in...? Good luck

[jps4jeep]

both are 93's apparently..

Great thing about jeeps, the more you will have to do in a auto to 5 spd swap is drill a couple pre-marked holes in teh fire wall forthe clutch assembally.

The YJ AX 5 is junk, the AX 15 is less junk.

Like Tony said (and I), just swap everything. Motor, trany, t case, wiring, and emissions.

[rockdaleTJ]

rockdaletj said:

I dontknow if you have the AX-5 trans in yours, but from what ive read about TJ's, putting a 4.0 in front of IT IS A BIG JOB.Not worth it in my opinion.

Ok i reread your post, i thought you were thinking of putting a 4.0 into your jeep...now i remember you already have one....SO you want to swap your trans/motor/tcase into a 2.5 body/frame....that sounds not as bad as I had previously thought.

[chrometj]

swap a big block l.ol

[jeepgod]

honestly anything is do-able but why would you? it is easier to buy a running 6 cyl ygeigh than swap all your stuff around. you have to ask yourself "can i really do this swap?" not that i am putting you down but it is a lot more complicated than just "swapping a motor / trans etc"

think long and hard.


and for the record a magazine did a similar story on this not to long ago (o forget which mag. exactly fourwheeler, i believe) when they did a cost comparison it cost more than just buying a complete 6 cyl yj.

[rain76king]

Unless you have the know how and friends that know how and the time and money.........Don't do it! The whole time I've been on this board my jeeps been down due to an engine swap...

[jps4jeep]

Honestly Rich, If you were able to teach yourself how to install your gears, I think you will not have as much as a problem as you might think you would. But I also would agree with others, it might be more cost effective to find a 6cy YJ instead of a swap and keep you YJ for parts. you do have in excess of 300K miles on that thing.

[PatriotYJ]

oh yea i forgot about the 300,000 miles on your swappee part....just sell both and buy one with what you need

[Bono426]

how can yousell something with 300k miles on it? do the swap! and buy a beater jeep for like 200 bucks while your doing the engine swap