Engine swap

[paddywagon]

I'm new to the board and I recently aquired a 91 wrangler with a blown 2.5. The drive train is stock so I assume it has the ax5 transmission. I would like to put a 4.0 in to replace the 2.5 and was hopeing someone could tell me if the transmission would match up and what else would be needed other than the obvious wireing harness for the engine bay and pcm. Thanks

 

[luis]

I'm not at expert but I think all the accessories like power steering and alternator won't match up. U will need a transmission from the 4.0. I think it would be easier to get a donor vehicle same year wrangler that way u have a parts stash

 

[Bounty__Hunter]

The AX5 will not work, nor will it hold up to the 4.0L engine. You will also need to cut the motor mount perches from the frame and attach new ones for the 4.0L engine.

You will end up with another run of the mill 4.0L jeep with a hacked up install when you could install a better powerplant, like a v8, for the same amount of work and expense.

 

[paddywagon]

Thanks, the responces are helpful. I'm looking to get this thing running with as little headache as possible before I decide if I'm going to keep it or not. I already have a line on a 2.5 but if the 4.0 would have gone in with no issues I would have gone that route. Still not sure what other problems I'm going to encounter, th thing was pretty neglected and beat on before it came into my posession.

 

[luis]

I have a jeep with a 2.5 in yet. I like it alot. I mean with the mods every one is doing on em it would help alot but its a solid engine. My jeep hasn't gotten stuck yet and its been thru some hairy stuff

 

[paddywagon]

Yeah...thats how i got the thing. The guy that had it appearently sunk it pretty good. It came to me on a flatbed with an explanation "I went through a bog and the thing just quit on me..." I drained 3 quarts of oil and about 4 gallons of water out of the pan and was unable to get the thing to turn over. I havent bothered to pull it apart but am fairly certain at least one of the rods is bent. Called the gy and tod him he needed a motor and never heard from him again. Long story short I now have a jeep.

 

[luis]

Ya he proudly blew the engine and didnt tell u. If he buried it then I would Change the transmission oil it gear oil and go through all ur axle gear and make sure no mud is in there either. Jeeps r made for all that stuff but of u have a leak then there is a chance water and mud can enter the engine transmission or axle gears

 

[paddywagon]

NO doubt its going to need a good going over but it seems to be in supriseingly good shape for a 20 year old vehicle. Im kind of looking at it as a restoreation project. Theres a few things that need to be changed, some wireing that looks like it was done by my four year old, some rather offensive stickers that need to be removed...but it should be fun.

 

[paddywagon]

a picture of the jeep

 

[luis]

It's a good looking jeep

 

[superj]

i agree

 

[patyj]

damn put an eight in it and be done that is a nice jeep

 

[O_M_Jeep]

If you want to get it running with as little problems as possible get another 2.5 and be sure to replace all the fluids in the transmission, transfer case and both diffs.

If you want to "just put in a V8", replace the rear axle housing, transmission, transfer case, wiring, exhaust , and engine and fabricate all the mounts (engine, trans, exhaust, ECM) and depending on your state it has to be an engine available from that manufacturer and be that year or newer with all original working emissions systems.

It's just a matter of how much work you want to put in to it, no matter what you do it'll be fun when its done.

 

[luis]

If you want to get it running with as little problems as possible get another 2.5 and be sure to replace all the fluids in the transmission, transfer case and both diffs.

If you want to "just put in a V8", replace the rear axle housing, transmission, transfer case, wiring, exhaust , and engine and fabricate all the mounts (engine, trans, exhaust, ECM) and depending on your state it has to be an engine available from that manufacturer and be that year or newer with all original working emissions systems.

It's just a matter of how much work you want to put in to it, no matter what you do it'll be fun when its done.

Yes. But did u c his jeep? It's nice. Any engine will get the thing thru almost anything I say almost cuz going thru a brick wall will prove to he a hard task

 

[O_M_Jeep]

Yes. But did u c his jeep? It's nice. Any engine will get the thing thru almost anything I say almost cuz going thru a brick wall will prove to he a hard task

I'm afraid I have no idea what difference how nice the outside is makes to the answer of his question.

 

[luis]

I'm afraid I have no idea what difference how nice the outside is makes to the answer of his question.

Lol I just wanted to point out he had a nice looking jeep

 

[paddywagon]

The whole concept behind the 4.0 was that being a stock motor I was hopeing that it would go in with no headaches. It is also a stock motor so if something goes wrong a phone call to my parts supplier has the part in my hand in 20 minutes or so. I can see the guy behind the counter scratching his head and asking "Did you say you need a upper radiator hose for a 91 wrangler with a 350?" Honestly...sometimes they seem to have a hard enough time getting me the right parts. I've been down the hot rod road enough times before to not really need to go there again, add into it my wife is ****ed enough that I decided to hold onto it rather than dump it and recoup what we were already owed...looks like another 2.5 it is. Maybe someday when the rest of it is put back together properly I'll look into a nice fuel injected dodge 360 but for now I dont need the extra headache.

 

[O_M_Jeep]

Another 2.5 is the easiest way to go, probably the cheapest depending on what you can get a new engine for. It would have been nice if Jeep had made them a little more interchangable. Time and again when you ask the 2.5 to 4.0 question most people just say "sell your 2.5 Jeep and buy a 4.0 Jeep", that doesnt answer anything at all, its just what they were willing to do

The easiest way to do the swap in all seriousness is to find that fabled "rolled over and totaled 4.0" that you can just switch tubs on, Ive yet to see one for sale.

One of the most respected places to look for used Jeep parts is daveysjeeps.com they have nothing but Jeeps and Jeep parts, but they know what their stuff is worth and your not going to get a 'pick and pull' kind of price.

Whichever way you decide to go, good luck, have fun with it, thats what Jeeps are about, fun, and thousands of extremely knowledgable people are here to help.

 

[paddywagon]

So a new (used) 2.5 is in and the jeep is running and on the road. It still needs alot of work, first and foremost being tires. Brakes and front end work wontt be too far behind. I'm going to need to replace the gas tank (leaks) and skid plate...it appearently had a stump put through (thus the leaking gas tank) not to mention it is pretty rotted out. For some unknown reason I found the fuel pump relay in the ac relay spot. Drained more water than I care to think about out of the transmission and differentials but oddly there was none in the transfer case.
But it is now back on the road and my five year old thinks it is the coolest thing ever.

 

[superj]

it is cool, man. i am glad its back on the road for ya'll to play with