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Transmission and transfer case?????


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If you've got a 2.5 4cyl then the 4wd ax-4 will keep you manual 4 speed. Grab a 4cyl np231 transfer case to go with it. The 4cy have less heavy duty parts and fewer spline count on the transfer case to transmission. For a while the early MJ & Xj 6cyl & 4cyl shared the same transfer case, at some point the 6cyl got a tougher transfer case. I couldn't tell you which year to look for off the top of my head.

 

Although it might be easier to find a ax5 (5 speed) transfer case combo.

 

Bascily any Cherokee or Comanche 4cyl 4x4 manual transmission will work. It has to be XJ or mj because the tail case is clocked for the transfer case to fit the body. The transfer cases themselves can fit a variety of jeeps.

 

I don't disagree the ax15 is the better transmission however the there is a lot to converting a 4.0 6cyl transmission to fit the 4cyl.

 

Also the 4cyl transmission seem to work better with the power bands of the 4cyl.

 

I know folks have cause to not like the ax-4 & ax-5 but they usually are tough enough for the 4cyl.

 

the parts search shows the 4 speed 4x4 (ax-4) interchanges 1984-1990

 

Any 4x4 4cy transmission should be a direct fit from 1984(?) they show 1987-1993 on the computer for the 5 speed , it actually should work beyond but I'm not sure of the small changes.

Just find a combo of ax-5 or ax-4 and np231, or maybe np242 if that was an option.

 

You can do a search for used transmission with car-part.com & Hollanderparts.com

You going to need a lot of parts to convert 2wd to 4wd, probably want to avoid to vacuum disconnect front axel too (aka CAD axel)

 

 

 

 

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The AX15 will not bolt to the 2.5L 4 cyl.  You'll need an AX4 for 4wd.  That was the 4 spd that came with the 2.5L

 

If you can find a bell housing from a Dodge Dakota 2.5L that came with an AX15 (don't know which yrs), then you can bolt an AX15 to the Jeep 2.5.

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There are adapter kits for the ax15 to 4cyl. The Dakota bellhousing probably works the best but can be hard to find , on eBay they'll go for $200.

The trick even with the right parts is lining up the shifter to the body correctly. I think many solve this problem with a aftermarket shifter.

 

In this case just about any 4wd AX4 or AX5 from 1984-early 90s should work.

 

 

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It will be MUCH easier to source an AX-5 than to find a 4WD AX-4. Why insist on another 4WD transmission? They are the same except for the 5th gear -- if you don't want to use 5th, just use the first four gears, but you'll have the fifth gear for those rare days when you're going downhill with a tailwind.

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It will be MUCH easier to source an AX-5 than to find a 4WD AX-4. Why insist on another 4WD transmission? They are the same except for the 5th gear -- if you don't want to use 5th, just use the first four gears, but you'll have the fifth gear for those rare days when you're going downhill with a tailwind.

My brother keeps telling me that if I go with the 5 speed, the car is going to be slow as hell..... he says my top speed will be about 55mph with a 4.5 in lift with 33in tires

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I am trying to decide what transmission to put into my 90 Comanche that has the 2.5 liter, and someone keeps telling me to get the ax4 4wd transmission, which is impossible to find, because if I go with the ax5, my top speed will be 55 mph. I am planning on putting a 4.5 in lift with 33in tires. What do you guys think?

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I am trying to decide what transmission to put into my 90 Comanche that has the 2.5 liter, and someone keeps telling me to get the ax4 4wd transmission, which is impossible to find, because if I go with the ax5, my top speed will be 55 mph. I am planning on putting a 4.5 in lift with 33in tires. What do you guys think?

 

What do I think? I think a 2.5L isn't enough engine to push 33-inch tires on the street, and especially not on the highway. With that setup, and the 3.55 gears that are behind that AX-4 transmission, you not only won't need fifth gear, you also won't need fourth gear. The 2.5L needs RPMs to do anything, which is why the 5-speeds came with 4.10 gears while the 5-speed and 4.0L combination had 3.07 gears. With stock tires, your 4-banger runs 2670 RPM at 60 MPH. Switch to 33s, and it'll be turning only 2250 RPM at 60 MPH. Even 4.10 gears won't quite bring you back to stock RPM.

 

https://docs.google.com/spreadsheets/d/1pHFuhGgj6dQDfzyfFJH5z7NCDLW2KX3ABQgAJr3lBvM/pub?hl=en&hl=en&output=html

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Best way to help you is to regear your axles, if your concern is speed,

Once that is done Then a 5 speed trans would be an ideal swap because you have that 5th gear to cruise when in highways speeds...

 

I have the 2.5 with a 5 speed 3.5" lift and 35s and i don't even use 5th gear, 4th gear is all I need but still struggle to get to even to get to 65-70mph...well I currently have 4.10s

 

Once I regear to 4.88s I know it'll be the difference I need to get back that little grunt these little engines have

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I am trying to decide what transmission to put into my 90 Comanche that has the 2.5 liter, and someone keeps telling me to get the ax4 4wd transmission, which is impossible to find, because if I go with the ax5, my top speed will be 55 mph. I am planning on putting a 4.5 in lift with 33in tires. What do you guys think?

If you're doing that you'd need to re-gear the axel. And/or upgrade the engine and transmission at the same time as the 4wd conversion. If you just want to add 4wd that's different.

 

 

As everybody said the ax5 is the ax4 gear to gear except for 5th.

 

I thought maybe you were trying to keep it original by keeping the 4speed, no benefit to keeping it really. Depending on what your goals are for the MJ you might want to go more drastic than just adding 4wd. You've got a lot of work to do just to get 4wd, if you want the big tires you would need to regear or swap better ratio axels in since you've got to source the front axel anyway. if your going that far you could swap the engine and go for a lot more power. The simpler project is just adding 4wd, engine swaps get a lot more complicated depending on which direction you go.

 

 

 

 

 

 

 

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Fina a entire 2.5(or 4.0) Cherokee(rolled, frame rotted,  engine blown, etc) then you will have all the many little parts you need.

It might cost a bit more up front.  But your going to have all the little things that will save you cash(and many trips to the junk yard) in the long run.

If the frame is rotted/cracked or the thing had a light roll you can still drive it and test stuff this way also.

You will have a load of extra parts that you can sell or "upgrade" the Comanche with. 

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