New MJ Owner, some ?'s

98XJ-ID · 12-18-2005, 12:27 PM

Hey fellas, I just picked up a 1990 Comanche Pioneer with 113K on the clock. Its got the 4.0 in her and a 5-speed. First question, is the tranny the AX-15?

I also own 2 other cherokees and had a question. Are the spring perches on the cherokees the same width apart on the axle as the MJ? I have a CryCo 8.25 I wanna put under the MJ and maybe do a spring over at the same time, it would be pretty neat if i didnt have to weld anything

Also, the Emission Maint light is on and I heard that is just a rip-off device which chrysler put in there to go off when they wanted you to replace the cat.

Ill think of some more ?'s for you guys but thanks in advance for any help.

1986Comanche · 12-18-2005, 12:57 PM

Quote:

Originally Posted by 98XJ-ID

Hey fellas, I just picked up a 1990 Comanche Pioneer with 113K on the clock. Its got the 4.0 in her and a 5-speed. First question, is the tranny the AX-15?

I also own 2 other cherokees and had a question. Are the spring perches on the cherokees the same width apart on the axle as the MJ? I have a CryCo 8.25 I wanna put under the MJ and maybe do a spring over at the same time, it would be pretty neat if i didnt have to weld anything

Also, the Emission Maint light is on and I heard that is just a rip-off device which chrysler put in there to go off when they wanted you to replace the cat.

Ill think of some more ?'s for you guys but thanks in advance for any help.

To answer your first question, Yes the transmission would be an AX-15 in a 1990 Comanche. The spring perches on the Comanche Axle are farther apart than the Cherokees. The uni-body is wider in the back on a Comanche. The Emissions light was to get you to take it to the dealer and get the oxygen sensor replaced I believe not the catalytic convertor. Hope that helps.

98XJ-ID · 12-18-2005, 01:01 PM

thanks for the reply, so should i get the o2 sensor replaced? or just unplug the light

just thought of another question, i hear talk about "chevy drop shackles" for lift in the rear, are these just regular chev shackles, or one used to do a shackle lift on an old chev?

1986Comanche · 12-18-2005, 01:09 PM

Quote:

Originally Posted by 98XJ-ID

thanks for the reply, so should i get the o2 sensor replaced? or just unplug the light

just thought of another question, i hear talk about "chevy drop shackles" for lift in the rear, are these just regular chev shackles, or one used to do a shackle lift on an old chev?

No problem. The Oxygen sensor probably could use replaced anyway, but that won't make the light go out. What the dealer would do is reset the timer that made the light come on. Then the light would be out after being reset. Personally I do not know how to do that. I have ever had to deal with that. You could just unplug the light and say the heck with it if you wanted to though. Yes I believe the shackles are regular fullsize chevy rear shackles and will give you 2 inches of lift in the rear because they are longer than the Comanches stock shackles.

Ed in North Ga · 12-18-2005, 04:22 PM

Quote:

Originally Posted by 1986Comanche

No problem. The Oxygen sensor probably could use replaced anyway, but that won't make the light go out. What the dealer would do is reset the timer that made the light come on. Then the light would be out after being reset. Personally I do not know how to do that. I have ever had to deal with that. You could just unplug the light and say the heck with it if you wanted to though. Yes I believe the shackles are regular fullsize chevy rear shackles and will give you 2 inches of lift in the rear because they are longer than the Comanches stock shackles.

FYI: its not a resettable- its a one time use device. To "reset", they "replace".
The easy route is to either unplug the harness, or remove the device and see how far you can throw it ( I prefer the overhand toss off tall building)...their preprogrammed for 70,000- some are programmed for 120,000...some are just plain whenever. Its a cute little box-really it is. It looks for all purposes like a glorified clock inside-with all the plastic cogs and wheels. one would think a technical wonder like it should be computerized...nope. If you remove/unplug/ect- SAVE THE BULB!
It fits into all the other sockets hidden behind the dashpanel...and its always nice to have one handy.
post 91 jeeps DO have resettable main. lights, pre 91s do not.
and like `86 says, its a nice way to ask you to take it to the dealer for a "check-up"- where they will want to do nice things that cost money...BUT, if you inform the nice people that you havent done ANY of the recalls on your 1990..and they look into their magical computer and find that none were done on your vehicle...they would be required to:
A: replace the 02 for FREE (and try to sell you a new timer)
B: replace the CCV for FREE (and sell you some tires/washer fluid/oil)
c: replace the TPS on automatics with crusie control for FREE (or tell you your nuts, go away-bring back money).

unfortunately, when doing FREE work, they are not required to be friendly...you have to pay for that.

They will also NOT give you the parts...you have to hand them the keys and make an appointment....bastids!

cj7xjmj · 12-18-2005, 04:24 PM

The rear spring perches are a lil over 5/8 of an inch to narrow. The best thing to do is to remove the stock ones, and either buy some new ones, or make some. Advance auto parts has a MR gasket catalog that has them listed for like 20 bucks. Also You are going to have to do something about your shocks.

As for the chevy full size shackles. I am running them, and have been for quite some time

Yes they are the ones for just about any newer style full size chevy. Heck I think the new 3/4 ton HD ones might me long enough in the stock setup, to make for a sizeable lift. I just haven't measured the ones on the jeep hlr yet to see if they would work.

Patrick

98XJ-ID · 12-18-2005, 04:35 PM

thanks for all the info guys.

about the cherokee axle and chevy shackle. i have a 98 which i rolled and have some parts on it suspension/armor/etc and im looking for a way to use some of theese. my MJ has the turdy-5 in the rear and i wanna ditch it. i wanna swap the 8.25 (not the greatest, but better than the 35 + it has LSD) from my 98' in the spring over fashion with the stock MJ springs. Im hoping for 5 inches, but will make up with the "chevy shackles" is it best to find 1" or 2" shackles for a newer 2500? or stock height ? im just trying to fit some decent sized all terrains for this rig for my DD since i rolled the nice DD. gotta have something to drive until i can get the welder i want to start on the XJ

any advice will be great.

josh

a4xnut · 12-18-2005, 04:36 PM

I was under the belief that the Chevy shackles in question are the aftermarket ones used to lower a Chevy... since their shackles are upside down compared to the design the MJ uses, a longer shackle on the Chevy will lower it and will lift the MJ.

DirtyCommanche · 12-19-2005, 01:34 AM

A spring over will easily net you 5+". Although, it will depend on which axle you use, which perches you use, how you hold your mouth, and your springs condition.

Chevy shackles are identical to MJ ones, IIRC. Although, when I told some XJ guy to use chevy shackles for lift he started saying "they'll bend, blah blah blah" so maybe they are different. Anyways, you want the lowering shackles for a full size chevy to give you lift. Although, some chevies might actually have the shackles the 'right' way up, so a lift shackle for one of them would give you lift. They're kinda pricy, so you might as well buy lift shackles for a cherokee (they'll come up about an inch less lift than advertised) if you're buying new. However, there's lots of tools in this world, so you can get chevy drop shackles pretty easy. Even I found a pair in a junkyard; although I realized I already have 8+" of lift in my back end now, so what does it matter.

Oh yeah, if you rolled your XJ, check those axles before you swap them! Tubes like to get bent in rollovers. If you didn't roll it, I'm jsut too tired.

Mhmm, sleep.

Pete M · 12-19-2005, 07:22 PM

Quote:

Originally Posted by 1986Comanche

The spring perches on the Comanche Axle are farther apart than the Cherokees. The uni-body is wider in the back on a Comanche.

Just an FYI, the Cherokee's perches are further apart than the MJ's due to the XJ having the leafs on the outside of the frame.
Jeep on!
--Pete

DirtyCommanche · 12-19-2005, 09:34 PM

Quote:

Originally Posted by Pete M

Just an FYI, the Cherokee's perches are further apart than the MJ's due to the XJ having the leafs on the outside of the frame.
Jeep on!
--Pete

This keeps screwing me up. So, I checked the FSMs frame diagrams, and well, guess what. MJs are wider, but only by 8mm. Hmmm, I must have read that wrong.

(that's outside of the pocket width)

Pete M · 12-19-2005, 09:51 PM

Interesting... Specifically which dimension is that? I don't understand the term "outside of the pocket"? The MJ frame is wider than the XJ's, but the XJ mounts the leafs on the outside of the frame so the perches are off by like an inch on either side.
Jeep on!
--Pete

DirtyCommanche · 12-19-2005, 10:26 PM

Well, the MJ frame widens, and has the pockets vertically inline with the frame. The XJ frame doesn't widen, but has the pockets outside of the frame.

I ment the measurements were from the outsides of spring pockets. I'd normally do center to center, but that wasn't going to be convenient.

The diagrams are a bish to read though, as they aren't ment for this... If I knew where my camera was I'd show you.

DirtyCommanche · 12-20-2005, 12:52 AM

I found the camera, so... (Sorry about picture size, but yeah...)

Comanche:

Cherokee:

Now, on the Comanche you have a listed distance of 1208mm between the outsides of the spring pockets with a tolerance of 1.5mm.

On the Cherokee it is listed as being 888.96mm from C to C of the framerails. Then, there's a farther 151.52mm on each side to account for the spring pocket. Thus, 2(151.52) + 888.96 = 1192mm.

Meaning, there's only an 16mm difference in width. (I was wrong before) That is, however, pretty neglible. Seeing as how it's only about 5/8th of an inch between both sides.

Tell me how I screwed up. I ALWAYS thought that cherokee/comanche widths were different.

cj7xjmj · 12-20-2005, 07:10 AM

Quote:

Originally Posted by cj7xjmj

The rear spring perches are a lil over 5/8 of an inch to narrow. .
Patrick

I thought I said that.

What I was saying is the stock Chevy shackles are taller then the MJ ones. If they are run on a ful size 3/4 ton truck they have to be pretty strong. Thats all I wil say on that.

BTW those are pretty cool drawings from a fabrication standpoint, especially if you know how to do the conversin from metric to english measurements

BTW I think 300MM equals 12" so do the math