Dakota ax15 to Wrangler

[complete_loser]

Hi ya'll.

I am in need of an Ax15 for my yj. Is the ax15 out of a 4x4 dakota the same, will it bolt up normal to my np231j?

Thanks in advance.

 

[TheGhost45]

Interesting question, I hope someone can answer this I would like to know as well then maybe I could do a conversion from my auto transmission to a standard

 

[jfrabat]

IIRC, the dakota bellhousing is used to swap the AX15 into the 2.5L Jeep, but I dont know the spline count on the Dakota AX15...

 

[complete_loser]

Heres what im doin. Im putting a small block chevy in my yj.
Im gonna get the adapter plate to adapt the ax15 to the sbc.

I have heard the dakota ax15 rear (where it mates to tcase) may be slightly clocked different than np231j position. ????

 

[jps4jeep]

the dakota AX15 should be a 21 spline. I assume you have a 6 cyl, so you currently have a 23 spline. either find a 21 spline 231 main shaft and swap it (super cheap) or find a t-case from a 4 cyl jeep.

 

[Bounty__Hunter]

Heres what im doin. Im putting a small block chevy in my yj.
Im gonna get the adapter plate to adapt the ax15 to the sbc.

Why not use a GM transmission and the 231c to save from buying any adapters?

The Dakota 2.5L bellhousing is common for swapping an AX15 into a 2.5L jeep, not sure what bellhousing and transmission was available behind other Dakota motors.

 

[complete_loser]

the dakota AX15 should be a 21 spline. I assume you have a 6 cyl, so you currently have a 23 spline. either find a 21 spline 231 main shaft and swap it (super cheap) or find a t-case from a 4 cyl jeep.

Thanks for the info. I currently have a 4banger. And also have an extra 21spline 231 layin around.
I just need to be positive that the dakota ax15 is identical and not clocked different before I go pull one from the junkyard.

Why not use a GM transmission and the 231c to save from buying any adapters?

I have considered that. But, not matter what route I take, my drive train OAL will be longer. With the jeep drive train, its easy to shorten with a SYE.
With the other routes (chevy transmission/tcase) SYE's are not as prevalent. I found a seller of SYE's on ebay, asked them if their SYE kit would work on a np231c, they said no.

 

[jps4jeep]

amhemm... you realize that a SBC is about the same length, water pump to bell housing as a 2.5L right...

I was unaware of a V8 being swapped in, an ax15 will not be happy and will not last very long. I would look for an NV4500 from a chevy (or sm465 if you do not plan on driving on a highway) will bolt up to the motor, pick a t-case since most anything can be adapted. you total length will be about what a 4cy with an AX15 and non SYE 231 will be.

 

[complete_loser]

amhemm... you realize that a SBC is about the same length, water pump to bell housing as a 2.5L right...

I was unaware of a V8 being swapped in, an ax15 will not be happy and will not last very long. I would look for an NV4500 from a chevy (or sm465 if you do not plan on driving on a highway) will bolt up to the motor, pick a t-case since most anything can be adapted. you total length will be about what a 4cy with an AX15 and non SYE 231 will be.

This SBC has no more hp/tq than the straight six. And the ax15 is longer than the ax5 which im currently running. Not counting the adapter plate I will use.
So therefore, OAL will be longer.
And this jeep will be driven highway only. Stock tires.

 

[Bounty__Hunter]

A SYE can be installed on a 231c but it may take a rear cover from a 231j. It can work easily. I would recommend upgrading the 231 to a 6gear planetary and a wide chain setup to handle v8 power. You can buy the parts from JB or source them from other transfer cases.

You can locate the v8 by keeping the transfer case in the stock location if you want to avoid any driveshaft mods or skidplate mods.

 

[volaredon]

A SYE can be installed on a 231c but it may take a rear cover from a 231j. It can work easily. I would recommend upgrading the 231 to a 6gear planetary and a wide chain setup to handle v8 power. You can buy the parts from JB or source them from other transfer cases.

You can locate the v8 by keeping the transfer case in the stock location if you want to avoid any driveshaft mods or skidplate mods.

I am wondering the answer to this myself for 2 reasons; but I MUST 1st say; Chevy engine to Jeep; MAJOR YAWN!

But more on-topic, I have a 97 TJ w/ a 4.0 that has dead synchros; I don't have time driving back n forth 85 mile round trip-a-day (I returned to college full time) to have it down long enough to pull the existing transmission, teardown/rebuild and then put it back up; I'm gonna have to pull and swap something right back in so as to keep down time to a minimum; I see more Dakota 4WD transmissions available than Jeep versions; I have an AX 15 now; if it is only a matter of a bellhousing swap, that's easy.

and I have a 2WD AX 15 from a Dakota sittin here and have a guy interested in it for a 2WD Cherokee. I don't wanna pizz the guy off by selling him somethin that won't fit.

 

[Bounty__Hunter]

They'll work if you keep the 4.0L bellhousing. You may need to swap the front bearing cover on the AX15 if switching from external clutch slave to internal or vice versa.

 

[jps4jeep]

First if your putting in a V8 that is putting out 180hp and 235 ft lbs, whats the point? sell your jeep and go buy one with a straight 6. Second, if this is the out put of the engine, your most likely sourcing a carbed (or early TBI) motor from a early-mid 80's chevy, I would check the legality in your state as in most states this is not a legal swap.

If you look closely at my comparison I clearly wrote that a V8 with an AX15 and 231 with SYE will be about the same length as a 4cyl with an AX15 and non sye, I did not mentioned the comparison between a AX5 and AX15. But I will have to check on the dimensions of the AX5-AX15,but the difference can not be much more than an inch or two. Over all weight and size of the NV4500 is ten fold, but lengthwise it is only a couple inches longer and would live happily behind any motor.

 

[jps4jeep]

They'll work if you keep the 4.0L bellhousing. You may need to swap the front bearing cover on the AX15 if switching from external clutch slave to internal or vice versa.

I think the aftermarket has addressed this with adjustable bearings that can be adapted to pretty much any manual trans. I would have to pour over the jegs catalog to verify though.

 

[complete_loser]

First if your putting in a V8 that is putting out 180hp and 235 ft lbs, whats the point? sell your jeep and go buy one with a straight 6. Second, if this is the out put of the engine, your most likely sourcing a carbed (or early TBI) motor from a early-mid 80's chevy, I would check the legality in your state as in most states this is not a legal swap.

Heres just a few reasons mother,

SBC easier to work on (not cramed into the firewall like the six),
Parts are cheaper,
Better weight distribution,
I have much more personal experience with fuel injected sbc's,
305tuned port roller engine is more efficient,
Every Jeep motor I have ever owned (3 over the years and several friends motors) blew oil out of the crank case, dip stick, valve cover, etc... (developed high crankcase pressure) as the motor wore out prematurely (compression leak down/blow by),
The Jeep motors drain down after shut down which causes premature wear,
The genius ccv system pumps condensation back into the combustion chamber (and or oil all over your air filter), mixing with oil, forming acids, accelerating wear,
And I happen to have a brand new tpi engine ready to go in something.

I admit, the jeep motors will run forever. It just aint pretty. Last six I had ran forever. It just wouldnt stop. Especially if you parked it on even the slightest hill. lol

 

[Bounty__Hunter]

I think the aftermarket has addressed this with adjustable bearings that can be adapted to pretty much any manual trans. I would have to pour over the jegs catalog to verify though.

I'm speaking of the cover in which the throwout bearing rides, it's different between external and internal slave.

 

[jps4jeep]

well, I am not your mother first off

second, I will not argue the cost of replacement parts, considering that from 1954-2002 chevrolet only used 2 water pumps on small black motors, a SBC is the best bang for the buck for replacement parts.

As for efficency, the tuned port 305 is not only not efficient, it is probably one of the least efficient v8 chevrolet has ever produced (carbed 305 probably being the worse)

As for the other issues you listed you had with your motors, I find those odd. I've driven Jeeps over the past 16+ years and have never had the issues you list, and this include a stock motor with about 230K. I have owned my current YJ since it was a year old, it is now a trail only rig, but gets beat pretty hard and with unknown milage, I have never had those issues.

another thing to consider is the legality, you mentioned this is a daily driver, the TPI 305 motor was in F-body's 88-92, I would just double check with your state regulations.

Good Luck with the swap, at least the ability to swap to a better SBC will be easily done.

 

[complete_loser]

Thanks for the tip on JB, Bounty! Awesome stuff!
jps4jeep, you misunderstood. "305tuned port roller engine is more efficient than the 4.0." As far as inefficiency (energy in vs: energy out) the internal combustion engine is only 1/3 efficient in general. As far as the most inefficient sbc, that would be an interesting article. The 400 probably takes that prize.



I found a guy with a nv3550 out of a chevy truck, but he dont have a tcase with it. If im correct, I would want a 231c with it, and then swap the rear case half with my 231j and throw in the sye. ?

 

[Jeep1985]

hey guys i happen to read your forum here and i believe you guys can help me if you would i have a 93 jeep wrangler with the 4.0 AX15 but the engine is how shall we say beat to a pulp from the previous owner.

i have a Dodge ram 1500 5.2 automatic sitting that i had bought for parts for my other pickup will that engine do a direct fit to the AX15 transmission something i have heard. i doubt it but you guys seem to know alot more bought the jeeps than I do.

 

[volaredon]

yeah it will with a Dakota 3.9V6 bellhousing; the bells are detatchable from the trans. the 3.9-318-and 360 share the same bellhousing bolt pattern. but are different from the 4.0 Jeep bell.