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engine and trani swap

1

19Pioneer86

NAXJA Forum User
Location
Ft. Worth, Texas
Ok here is the deal I have a 86 xj and it currently has the 2.5l 4cyl (150ci) and the 5spd trani.... Now for the question part... I am wanting to switch over to the 4.0l I6 but i need to know if my current transmission will bolt up to the bigger engine or for that matter can it take the extra power i know it may not be much more power but i do a-lot of wheelin and this vehicle is my dd/weekend toy so i need it to be reliable i had to replace the 1st and 5th shifter arm in my first xj (85 same engine and trani but it was carb instead of TBI) and it took them 6 weeks to get my part in on account that it is a dealer only part and had to "special order it" so wll this work or will i have to change the trani i am just asking before i put the engine in there and then it not bolt up and me not have a trani for another 3 weeks. oh yea and second question the cj/tj/ w/e transmissions (5spd) will go right into my xj w/o any cuting right i mean in the hole in the floorboard where the shifter comes through taht way i know if i can get a trani or not outta one of those as well giving me more options on parts.

thanx,

Trent
 
1. 86XJ+4.0=lots o' work.

2. You'll have to cut a hole for the ECM connector...not too bg of a deal, but still, it's a nice hole.

3. Unless you REALLY want an AMC XJ, I'd look for a 87+ for cheap.

FWIW, Mine is an 86 2.8 w/228 case, 220,XXX miles, and is a rock.
 
so i could put the 2.8 v6 pretty easy? or even the 2.1turbo diesel (does anyone have one and could drop some reliabity info) and the 4.0 is hard because they didnt come with them? so where is the hole at that i hev to cut? and how would i go about sealing it? and what all do i need to do it. I want the toque from the straight six but if it is that much easier i may opt for the 2.8 V6 if its as good as you say.
 
V6 good? BWAHAHAHAHHAHAHAHHAH

It runs, and with 3.73 gears and 31's will *JUST* pull it at 70....With a good tailwind.

2.1 TD...fuggedaboutit. They are like 2K JUST for the block.

4.0 is a pain, because it was not designed to have a long narrow motor in it in those years.

2.8 would even be a hard one,due to the rare tranny needed...(TF999 drilled for a GM 60* bellhousing)

If all you want is the power of the 4.0, just buy one..they are like 500-1K around here for a 87-92...Save you the headache, and drama.
 
Since when do you have to cut a hole for the ECM. I did an 85 2.5L to a 88 4.7L stroker swap and had no such issues. On the years before the XJ had the 4.0L, the front radiator support and some major sheetmetal work up front is required, as well as the hood is different and has to be changed along with using a BFH on the firewall.
 
old_man said:
Since when do you have to cut a hole for the ECM. I did an 85 2.5L to a 88 4.7L stroker swap and had no such issues. On the before the years that had the 4.0L, the front radiator support and some major sheetmetal work up front, as well as the hood his different and has to be changed along with using a BFH on the firewall.
Click to expand...

D'oh.....Was thinking an 85(brain fart)

But, yes, major hammer work is needed if you cannot get the core support, and pretty much the front end off of the donor.
 
an 87+ cherokee 4x4 around here with the 4.0 that runs is 1300-2300 and thats just for one that runs not runs well but runs and drives... so thats not gonna be affordable...

1) what hood will i need?
2) what all is included in "major sheetmetan work up front?"
3) why do i have to beat in the firewall?
4) where will the ecm have to go?
 
19Pioneer86 said:
an 87+ cherokee 4x4 around here with the 4.0 that runs is 1300-2300 and thats just for one that runs not runs well but runs and drives... so thats not gonna be affordable...

1) what hood will i need?
2) what all is included in "major sheetmetan work up front?"
3) why do i have to beat in the firewall?
4) where will the ecm have to go?
Click to expand...

You do not need to change the hood, but you will need to revise the center latch.

The entire radiator support framework has to be cut out, and replaced with the corresponding parts from an '87 or newer XJ in order to move the radiator far enough forward to make room for the longer engine, and to provide enough width for the much wider 4.0L radiator.

You have to beat the firewall because in your year it was not configured to fit around the longer angine and larger bellhousing of the 4.0L setup.

The ECM mounts inside the vehicle, under the dashboard, if you go with an engine from a Renix XJ (87 thru 90). The newer ones mount under the hood, on the left inner fender between the air box and the sheet metal.

In addition to the body work involved, you will also need to do extensive rewiring. The people who advise you to just buy a 4.0L vehicle are trying to do you a favor. Don't write off that advice. Unless you are very experienced in all phases of automotive repair (engine, bodywork, and electrical), trying to do this swap is going to cost you a lot.

If you want to keep your existing XJ and get more power, the best swap is a Chevy 3.4L V6 out of a REAR WHEEL DRIVE car like a Camaro. It's the same basic block as the 2.8L, uses the same bellhousing bolt pattern, and is much more reliable than the 2.8L.
 
Eagle said:
You do not need to change the hood, but you will need to revise the center latch.

The entire radiator support framework has to be cut out, and replaced with the corresponding parts from an '87 or newer XJ in order to move the radiator far enough forward to make room for the longer engine, and to provide enough width for the much wider 4.0L radiator.

You have to beat the firewall because in your year it was not configured to fit around the longer angine and larger bellhousing of the 4.0L setup.

The ECM mounts inside the vehicle, under the dashboard, if you go with an engine from a Renix XJ (87 thru 90). The newer ones mount under the hood, on the left inner fender between the air box and the sheet metal.

In addition to the body work involved, you will also need to do extensive rewiring. The people who advise you to just buy a 4.0L vehicle are trying to do you a favor. Don't write off that advice. Unless you are very experienced in all phases of automotive repair (engine, bodywork, and electrical), trying to do this swap is going to cost you a lot.

If you want to keep your existing XJ and get more power, the best swap is a Chevy 3.4L V6 out of a REAR WHEEL DRIVE car like a Camaro. It's the same basic block as the 2.8L, uses the same bellhousing bolt pattern, and is much more reliable than the 2.8L.
Click to expand...


All good advice, but he' got a 2.5. The v6 is just about as much work to swap.
 
19Pioneer86 said:
an 87+ cherokee 4x4 around here with the 4.0 that runs is 1300-2300 and thats just for one that runs not runs well but runs and drives... so thats not gonna be affordable...
Click to expand...

Neither will an engine swap. By the time you've bought the engine and materials for the swap, and done the fabrication needed to get the 4.0 into the '86 engine bay, you'll end up spending more.
I agree with Storydude. Look a round for an '87-'90 4.0 XJ. You should find a runner for less than a grand, and keep your existing XJ as a donor for parts.
 
Ok eagle posted that i would have to do extensive wiring... but did any of the older wranglers come with the 4.0? because i would like to run a carburator setup as opposed to fuel injection simply because of the wiring and electrical i know engine work and i have some welding skills (for body work and a saws all) and i know enough about electrical i could do it i just wouldnt be having any fun. but is it possible to run a carb and no emmisions instead meaning no egr and bs like that?

you guys are being a big help thanks for the much need advise allready.

Trent
 
The older 'square headlight' YJ Wranglers had 4.2l carb'd and the 91+ ones had the 4.0HO. Both would have the same fitment issues to deal with as an XJ 4.0, and I don't think his AX5 transmission is going to mate with either. So, he's looking at an engine, clutch, tranny, t-case, etc..

As Eagle says, the 3.4 GM V6 (Rwd Camaro or 'Bird) is a viable swap, that retains the existing transmission/case. Basically add exhausts with 02, mount & plug in the computer/harness from the donor, and I'd guess an electric fuel pump to keep it fed.

Either way, plan on getting "everything" from the donor vehicle(s)

I'd agree with the above... if one wants a 4.x liter I-6, it's best just to get one of the appropriate year and build on that platform. If the 86 runs well, keep it around while you build the 6-cyl. I'd think one could find a good one for less than a completed engine swap will cost.
 
Correct on the tranny. The 2.5L I4 uses the same small GM bell housing bolt pattern as the 2.8L V6. The 2.5L tranny will not bolt up to the 4.0L (or 4.2L) block, and the AX-5 tranny wouldn't live for long behind either of those engines even if you adapt it.
 
damn pre 4.0 engine cherokees... ok so i found a 91 cherokee with the 4.0 and auto transmisssion... and its 4x4 and they want $3200 is this fair? now i live in texas so most everything down here is more expensive becasue nothing really has rust unless its been sitting in a field so is this a good deal? my 2.5 barley runs and the rear main seal is trashed i leaks about 1/16-1/8 qt of oil after i shut if off just from driving around the block.... and sugestions are very much welcomed and i have checked the junk yards and knowone has the 2.5 that runs so am i just sol?

Trent
 
$3200 isn't bad but you might be advised to ask a competent mechanic to go over it with a fine toothcomb to identify any defects in the Jeep (you can guarantee that there'll be at least one or two). That way you can estimate the cost of rectifying those defects and deduct it from the asking price.
 
www.edmunds.com

They have a calculator to tell you the average selling price for used cars in your area. Don't know if they go back more than 10 years, though. IMHO, when you get much over ten years the books don't apply. The "fair" price comes down to what a willing buyer offers to a willing seller. If it's worth $3200 to you, it's worth $3200.

FWIW my friend Eshel in Texas says 4WD XJs are hard to find, so if this one is 4WD and looks to be in good shape, it's probably your truck.
 
I am a mechanic :wave: ... just some thing i didnt know becasue of no schooling :conceited... its ok i know more than the other guy i work with that went to school... ok that was dumb and off topic... ok so i found anothe jeep that i think i am prolly gonna buy... on rustysoffroad.com its under "rustys rigs" and its jeep number 73... ok it has 34 swamper tsl's now and about 8 in of lift and not 10 anymore... here is the problem the guy that has it now got it in a trade and i dunno if he really knows whats goin on with it :dunno: ... oh yea and the axels are the factor dana 30front and 35rear w/ the 3:07 gears... ok well when you get up to about 27mph(on the uncalibrated spedo) and hit a bump it starts to bounce then gets worse and worse... well the guy said "worn ball joints" ok possibly but not as bad as this thing bounces so i looked at the pinion angle and the axels have no shims on the to change the angle and take some of teh angle off of the u joints and sitting still the angle looks sorta extreme so when you hit a bump and the axle drops a lil more it is gonna bind up forcing it to push back thus starting a "bouncing motion" that just gets worse and worse till you slow WAY WAY WAY down ok so the guy replaced the stering stabilizer shock and fig that it may help it didnt... :lecture: so if i just shim it it will take the angle off the u joints and will prevent them from binding up thus stopping the "bouncing motion" :lecture: havent had time to ask anyone else in person cept for my dad who said it should work just wanted to get some more opinions before i went and put down an offer on this thing... better safe tahn sorry could save myself money in the long run... thanks long day and sorry if i sounded rude and it was really long. :speepin:


Trent

p.s. im havin fun with the smileys :party: :smoker:<--- who doesnt have that habit...
 
19Pioneer86 said:
I am a mechanic :wave: ... just some thing i didnt know becasue of no schooling :conceited... its ok i know more than the other guy i work with that went to school... ok that was dumb and off topic... ok so i found anothe jeep that i think i am prolly gonna buy... on rustysoffroad.com its under "rustys rigs" and its jeep number 73... ok it has 34 swamper tsl's now and about 8 in of lift and not 10 anymore... here is the problem the guy that has it now got it in a trade and i dunno if he really knows whats goin on with it :dunno: ... oh yea and the axels are the factor dana 30front and 35rear w/ the 3:07 gears... ok well when you get up to about 27mph(on the uncalibrated spedo) and hit a bump it starts to bounce then gets worse and worse... well the guy said "worn ball joints" ok possibly but not as bad as this thing bounces so i looked at the pinion angle and the axels have no shims on the to change the angle and take some of teh angle off of the u joints and sitting still the angle looks sorta extreme so when you hit a bump and the axle drops a lil more it is gonna bind up forcing it to push back thus starting a "bouncing motion" that just gets worse and worse till you slow WAY WAY WAY down ok so the guy replaced the stering stabilizer shock and fig that it may help it didnt... :lecture: so if i just shim it it will take the angle off the u joints and will prevent them from binding up thus stopping the "bouncing motion" :lecture: havent had time to ask anyone else in person cept for my dad who said it should work just wanted to get some more opinions before i went and put down an offer on this thing... better safe tahn sorry could save myself money in the long run... thanks long day and sorry if i sounded rude and it was really long. :speepin:


Trent

p.s. im havin fun with the smileys :party: :smoker:<--- who doesnt have that habit...
Click to expand...

That Jeep sounds like it's gonna be a money pit. Plus, the combination of 34's with stock D35 rear and 3.07's is not a good idea. The 8" lift and all the problems associated with it in this truck tell me that this is one to avoid.
 
ok well i was allready planning on changing the gears in it and sown the line the axels as well (as money permitted) but as far as the wiring a buddy of mine and me can knock that out in like 2 days if we sit and work and since we prolly wont i give it about a week cause we will just end up drinking... and as far as the lift goes all i need to do is shim it right? if thats it as far as the bouncing then lets do it he isnt asking hardly anything on the jeep it runs and drives great (-the bouncing) and i took a look at the ballboints and they look like theyre in excelent condition the boots and things arnt cracked or nothin so i really think its the pinion angle and thats a $60 fix and about an hour of work. so it will be realitivly cheap to make a dd and realy cheap just to fix the angle and make it ok to take off road.
leme know what u think one more time please.

p.s.other people can put in their 2 cents as well...

Trent
 
You mean the rhinolined one? It's got 4 inch blocks in the rear, yuck. Gonna be a lot of axlewrap with those blocks which will give ya hop. According to rustys site is has 4.88 gears and detroit lockers.

Sarge
 
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