Interested in buying a 91-92 MJ, got ?s

Iam looking to buy a pickup in the future so I want to start planning now. I like the 91-92 Comanche because it has a fuel injected 4.0 and comes in 4x4. I also heard about a "big ton payload" package that has a D44 rear axle. I would like to do some light offroad mods to it , but for the most part use it to flat tow my YJ within 150 miles of my home in San Diego. Here are my questions: 1) Is an MJ going to be able to flat tow my 4 popper YJ?
2)Are MJs with D44 rear ends hard to find?
3)If the MJ had a D35 rear end could it still tow my YJ?
4) How much money would I be looking at spending?
Thanks in advance for any help. :skull1:

Any year MJ '87 up will be a fuel injected 4.0, but the '91-'92 is the HO version. IMHO the Renix version ('87-'90) has the torque down low where it is better for towing anyway. You won't find a D44 rear (unless it was swapped in) in a '90 or newer. You could still tow with a D35, and D44's are just as hard to find on MJ's as they are on XJ's, if not more so since much fewer MJ's were made to begin with. I used to flat tow my lifted XJ with my MJ before I got my Suburban, so I see no reason why one wouldn't pull your YJ.

I have a '87 MJ longbed 4.0 4x4 5-speed with D44, 3.55 gears, skid plates, tow hooks, push bar, hitch, cap, bedliner, 3" lift, 31's on chrome rims, CD player with a good body available. It runs well w/ just over 200k miles on it, and I can include an additional 4.0 and automatic transmission w/ conversion parts if you are interested.

I am not an MJ owner but have read a lot on here about them. Just to make sure you do not overlook a MJ that will do the job.

84-86 XJ/MJ came with a 2.5 liter carborated I-4 or a 2.8 Liter V-6
87-90 XJ/MJ came with a Fuel Injected 2.5 liter I-4 or a Fuel Injected 4.0 liter I-6 engine
91-92 XJ/MJ came with a Fuel Injected 2.5 litre I-4 or a Fuel Injected 4.0 Liter HO I-6 engine

If you want a 4.0 liter MJ you can look at 87-92 not just 91-92. The 87-90 4.0 use the renix engine control, this engine is called the non-HO on here. The 4.0 HO use the chrysler engine control. Both engines are fuel injected and the non-HO has a different cam which gives you more low in torque - just what you want to towing. Also the Renix system has a knock sensor so if you get cheap gas your timing will be retarded. The chrysler system does not use a knock sensor and people post they have to run mid grade or high test to avoid knocking. There are more after market parts, accessories for the 4.0 HO engine.

I know 87-92 all use the AW-4 Automatic Transmission but different manual transmissions were used. Since I have an automatic I have not paid attention to the cut off year for manual transmissions.

The towing limits may be different on an MJ but on an 88 XJ any configuration can tow up to 2000 lbs - 4 or 6 cylinder, automatic or manual transmission. To tow up to 5000 lb - 3500 on a ball hitch/5000 on a wt dist hitch - you have to have the 4.0 engine, AW4 transmission - no manuals allowed, heavy duty cooling, Aux trans cooler, minimum size tires, along with some other stuff.

The reason I have read for the manual trans being limited on towing has to do with the clutch hydraulic system. That the weak link I have read and at heavy load you may not be able to disengage the clutch.

Also people talk a lot about axles and the Dana 35 being weak. I am told by guys on here it only a problem with oversized tires. If you keep a stock tire size then you will be fine. In 88 you could get a 75R15 tire delivered in P195, P205, P215, P225 and P235 listed in the shop manual in the speedo gear.

If you are wondering you may want to call techauthority, do a google search, and talk to them. Order the owner's manual for the years of MJ you are interested in. Read the manual and find out for yourself. Also once you buy your MJ order the shop manuals from techauthority, they are well worth the $100 you will spend.

I do not know what you'd pay for an old MJ but you may find a diamond in the rough. Don't worry about the paint too much, late 80s paint sucked anyway. Also if you are willing to repair something you may get a bargain.

Just a minor note, 86 XJ/MJs came with the fuel injected 2.5L not the carbed one.
If you know somone with a welder (to weld on new leaf pads), a Ford 8.8 axle from a 95+ Explorer can be used and give you disk brakes and posi-traction. Plus, it'll give you an opportunity to upgrade your gear ratio (don't forget that you'll need to re-gear the front too), which can be the best thing you can do if you plan on a lot of towing.
Get yourself a longbed. The extra wheelbase is a plus. Oh, and reciever hitches are much easier to come by (does anyone know of a hitch for the shortbed?) and you'll get a bigger gas tank.
What you should look for depends on what you can do after the purchase to make it exactly what you need. Try research on autotrader.com for going prices. Does rust bother you at all?
Jeep on!
--Pete

88 project MJ, 86 worker MJ, 89 parts MJ
http://autos.groups.yahoo.com/group/jeepcomanche/

I have a Putnam receiver hitch on my '87 shortbed, and a Brand X tube bumper with receiver on the '88. Why would a hitch for a shortbed be different from one for a longbed? Both of mine mount to the stock bumper mount bolt holes, and as far as I know the shortbeds and longbeds used the same bumpers.

It's just something I picked up after noticing a couple hitch manufacturer's lists where they mentioned the longbed but not the short. Shouldn't hitches bolt to more than just the stock bolts? I don't have a hitch so I'm out on a limb here. I'm not sure I could trust those tiny little bolts with my trailer.
Jeep on!
--Pete

Pete M said:

It's just something I picked up after noticing a couple hitch manufacturer's lists where they mentioned the longbed but not the short. Shouldn't hitches bolt to more than just the stock bolts? I don't have a hitch so I'm out on a limb here. I'm not sure I could trust those tiny little bolts with my trailer.
Jeep on!
--Pete

Click to expand...

Dunno. Worked for me towing a car trailer sized for a Caddy limo with an XJ on it. The dicey part was that my MJ isn't wired for the trailer brakes, so stopping required lots of advance notice. Hitch worked fine.

Heck, the stock step bumper is rated for a 350-lb tongue weight and 3500 pound tow weight.

That Putnam hitch currently on one of Eagle's shortbeds, originally came from a '88 longbed that I parted out, so they are interchangeable.

Wow, thanks for all the good info guys. I'm planning on one in the next year or so. I just like to start my shoping early and hold out for that one deal of a lifetime. Thats how I found my GFs XJ, months of searching until I found that one jewel on this forums forsale section that already had all the goodies. Now that my household has 2 moderatley built rigs, XJ and YJ, I obviously need to expand my collection and what better to expand it with than a MJ? How well does a Ford 8.8 fit into a MJ? I've been planing this swap for my YJ since the explorer is SUA and has the same position spring plates. But aren't MJs SOA? Would welding be needed(beside the pinion)?I was looking at the M715 before, but they seem like too much work to get going and cost too much initialy to buy. By the way7 how good of a wheeler is the MJ when moderatley built( 3-4" lift, 31-33" tires)?Thanks again for all the detailed responses.

MJs are spring under, and the leaves are mounted slightly inboard compared to XJ leaves. Shock mounts would be needed if they're not on the spring plates for the 8.8. MJs are great, I wish I still had one. It scraped the hitch often when it was stock, and I was glad I had rock sliders, but it was still great for me.

I just checked out Kelly Blue Book for some prices. An 87' with a 4.0 ,4x4, tow pkg,and 150K miles was only $1100. A 92' with a 4.0, 4x4, towpkg, and 100k miles was only $1900. Will I be able to find any canidates for blue book value? If I can I will buy one for sure, seems like alot of truck for the price. I really want one now.

Autotrader would probably give you a better idea of the going rates. 15 years old vehicles tend to fluctuate in price based on conditions that KBB can only guess at. Though I'm sure the KBB prices can be used as a bargaining chip if the guy is asking too much.
Putting the 8.8 in to an MJ is about the same as a YJ, but you don't need to weld on shock mounts. The Comanche uses a plate to mount the shocks and that plate can be transferred over to the new axle. You will need to weld on new leaf mounts no matter if you are going SOA or keeping it SUA.
When wheeling, the added wheelbase can be both a bane and a blessing. You'll want to add the aforementioned rock sliders cause the breakover angle is poor (compared to a YJ), but the longer wheelbase can mean the MJ can walk up an obstacle that gives a shorter Jeep problems. I would recommend sticking to 31s depending on what gearing you end up with. They fit great in the stock fenders and 31s + 4.10s + 4.0L + towing = . 33s only give you 1 lousy inch more clearance, but greatly increase the headaches and the amount of sheetmetal you'll be trimming off the fenders. I have 33s, 4.10s and a stick, and I dream of 4.88s.
Don't bother buying a cherry rig if you plan on being rough with it. Save your money and get one with a moderate amount of rust (pay attention to the floorboards and the rear fenders, that's where rust starts). Heck, you don't even need to buy a 4x4 if you want a real project truck. My 88 used to be 2wd but it sure ain't anymore. The truck has 180K+ miles on it but my TJ AX-15/NP-231 only have 5K, my Ford axles only have 54K, and my "new" block will only have 127K. Seemed better to me than buying a truck where everything is already high-mileage. It can be a bolt-in conversion if you stick with Jeep parts. 2wds with a bit of rust or a trashed tranny can be had for a song. I bought my OK-condition 2wd 127K mile '89 for $350 because it had a manual tranny with no reverse. I almost got a 2wd 91 with a blown engine for $100. It all depends on how much effort you want to put into your project.
Jeep on!
--Pete

Eagle said:

Heck, the stock step bumper is rated for a 350-lb tongue weight and 3500 pound tow weight.

Click to expand...

Where did you find that info? I can't find it anywhere. My dealership brochures state that the dealerships can install class 1 and class 3 hitches, but it doesn't say anything about the stock bumper. And the ratings are 200/2000 for C-1 and 750/5000 for C-3. 350/3500 doesn't show up on the page. (I think those numbers are for class 2, yes?) 3500 lbs seems awfully high for a bumper made out of formed sheetmetal. My 88's bumper (back when it was still a stock 2wd) was tweaked as a result of towing a car a few miles with a strap. Granted that there's more shock load with a length of strap than with an attached trailer, but I remember being extra cautious cause the truck was still new-to-me. I wouldn't trust that bumper for *anything*, especially if there's any evidence of rust. Hitches are cheap. Anyway, this is what I'm talking about. This site specifically lists the longbed, but makes no mention of the short for Hidden Hitches. Does Putman still make a hitch for the Comanche? Their website didn't list any.

Hidden hitch

http://store.yahoo.com/hitches4less/1919jeepcomc.html

Aren't the spare tires in slightly different locations between the long and shorts? That might make a particular design unable to be mounted on the shortbed cause it'd interfere with the tire.
Personally, I would prefer one that made use of that big shackle bolt. Anyone know of one that does?
Jeep on!
--Pete

Pete M said:

Where did you find that info? I can't find it anywhere.

Click to expand...

I guess I imagined it, because I just checked the owner's manual and it says the step bumper is equal in capacity to a Class A hitch - 2000 pounds capacity, and no mention of tongue weight.

Does Putman still make a hitch for the Comanche? Their website didn't list any.

Click to expand...

Dunno. I know the hitch I got from Lawn 'Cher is a Putnam because it still had all the labels on it. Couldn't tell you if they still make them.

BTW -- the hitch in the image you linked is an XJ hitch, not an MJ hitch.

Aren't the spare tires in slightly different locations between the long and shorts? That might make a particular design unable to be mounted on the shortbed cause it'd interfere with the tire.

Click to expand...

I don't think so. They all use the same spare tire winch, and that's set up to use the stock jack handle as a crank. So the location couldn't be very different.

I checked auto trader and the prices were a little ridiculous for even the high mileage 2wds, then again they were mostly used car dealership listings. Converting a 2wd to a 4x4 is a little ambitious for me at this point, besides I live in an apartment and can't do work like that in the street. You guys sure do know your stuff. What Ring And Pinion ratio does a 4.0 have, 3.55 0r 4.11?I probably won't go bigger than 31s for a tow rig. A long wheelbase will be fun in TruckHaven Hills. Will a auto locker, like a lockrite, make towing more difficult? Thanks again for all the info guys.

Diablito said:

What Ring And Pinion ratio does a 4.0 have, 3.55 0r 4.11?

Click to expand...

The 4.0L in an XJ or an MJ always came with 3.07 gears if mated with a 5-speed, and 3.55 gears if mated with an automatic.

Will a auto locker, like a lockrite, make towing more difficult?

Click to expand...

Yes. In fact, the locker manufacturers pretty much all say not to run a locker when towing. If you expect to tow a lot, get a decent limited slip rather than a locker. Or an ARB or OX selectable locker, if your budget can handle it.

3.07 is pretty high gearing. I guess if I get one I can swap swap my YJs 4.11s and their carriers into the MJ axles when I drop down to 4.88 in my YJ. I'll keep it stock till then. After a gear change though, 4" lift, 31s, new bumpers, and rocker guards. That'll be a sweet tow rig and decent offroad toy to boot. How great would it be to have a 3 Jeep household.

Hey I just thought of something. If I regear my Girlfriend's XJ, she is on 31s so lets say 4.11, could that flat tow my YJ?

Diablito said:

3.07 is pretty high gearing. I guess if I get one I can swap swap my YJs 4.11s and their carriers into the MJ axles when I drop down to 4.88 in my YJ. I'll keep it stock till then. After a gear change though, 4" lift, 31s, new bumpers, and rocker guards. That'll be a sweet tow rig and decent offroad toy to boot. How great would it be to have a 3 Jeep household.

Click to expand...

I have a three Jeep household. We want a five Jeep household, then it will probably be a six Jeep, and so on and so forth. Its a disease!!! :laugh:

I have to say, I probably know more about 4.0l Jeep parts than the people at the parts store, or at the stealership.

I'm sure it's been done, but the extra wheelbase of the MJ makes for a much safer tow rig, especially if you're flat towing.
Oh, and you can't just be swapping gear sets around in your Jeeps. Gears need to be "set up" properly and if you haven't done that before and don't have the proper tools, then I don't recommend it. There are only 2 things I'm not willing to try myself, rebuilding an automatic and setting up gears. Some things are best left to the pros. And I'm told that used gears should not be reused in another axle anyway. They develop a wear pattern in the first axle and they won't match up quite right in the second and will most likely whine a lot. The Dodge dealership reused my old gears in my Dakota when they replaced the posi unit (and carrier in the process) under warrentee and the whine was loud and annoying. Idiots. I didn't even make it to the first light and I turned around and had to give them my truck for another 2 days. I was not a happy camper. :smsoap: Why didn't they test drive it?
Anyways, back to the topic at hand, swapping entire axles can be preferable to getting new gears installed. 4-popper MJs and XJs generally came with 4.10 gears and that would match the Ford rear (make extra sure that any axle you buy truly is a 4.10 before you leave the yard, or at least get a good return guarantee on it).
Jeep on!
--Pete

P.S. Eagle, it just now dawned on me that my 89 SB might still has the stock tire carrier in place (I've removed the one in the 88). I compared it to my 86 and there was a 4 inch difference between the carrier center and the rear of the bed. Might be a big enough difference for a hitch, but none of my MJs has the stock jack, so I can't compare those.