XJ/MJ Concerns

Ok I will try to keep this short but no promises. About a year ago my wife and I decided that we wanted two similar vehicles that would last us a very long time , our hope was to not have to replace them unless they where stolen or damaged in a accident. Our requirements where , classic looks , DIY friendly strong reliable engine/drivetrain , solid axles front and rear, four doors for her two for me. So after searching for about six months we decided our vehicles would be a 2000 Jeep Cherokee for her and a 1989 Jeep Comanche for myself. The Comanche would be a more involved project a ground up rebuild including updating the sheet metal to 2000 pieces as well the complete drive train would updated to new pieces. So while I'm building this I purchased a left over 2006 Unlimited Wrangler to be my daily driver. work truck.

So I purchased a 2000 Cherokee with 100,000 miles on that was extremely clean it was previously owned by a navy officer who used it to commute between bases so it was never abused. I stared the minor mods we where planning on the Cherokee which include a OME lift w 245/65 BFG AT' a Dana 44 rear with ARB locker , ARB Bull Bar, rear bumper with tire carrier and a set of Detours off road slider - unibody stiffeners.

Before starting these mods I wanted to make sure the truck was in all around good order which it is , a few very minor items need attention nothing major. One of the small items is the drivers door hinge is toast , not pulling away from body rather just worn out from alot of opening and closing. No problem body shop is going to take care of it for $250.

Ok here's where my concerns come in , after reading a few things online and speaking to a few body shop guys I'm under the impression that the unibody on the Cherokee will with out a doubt ultimately fail even under normal use. My plan included unibody stiffeners which I thought would help eliminate any unibody problems , now I'm being told these will only make it worse. I've been told that the unibody will fail at the A pillar , effectively bending down and destroying the truck. This is under normal use meaning a grocery getter , I plan to use this truck for my wifes daily driver and a family camping rig that will see regular use on an off road. Nothing major but certainly above average use.

The only fix I've been offered is to cage the truck , which really isn't something I want to do. So here is my dilemma if this is true then these are not the long term trucks I was planning on building so I would rather get out of them now rather than put any more time or money into them. If this is inaccurate then great , I just need to get a definitive answer because I plan to have these trucks for a minimum of 20 years. Thanks for reading my unbelievably long post , and any help anyone can provide is much appreciated.

Don't know where you are getting your info, but I don't think it's accurate. There are guys on here that still wheeling late 80's XJs with undamaged unibodies. I also can't see where the sliders would hurt anything.

Ditto here.

I've spoken to guys who wheel 85's and up and have for years with no body failure.

It's a given that if you like twisting up your rig (say in rock-crawling), it'll strain the unibody and will start to crack at stress points; but daily-driver? No way. Want an example? Do a search on 'Jeepspeed' and look at what they put their Jeeps through. They stiffen up the unibody with plates and a cage, but holy crap can these trucks take a pounding!

I know Comanches might have trouble with cracks at the framerail/cab meeting area, but that's easy to fix with a little plating.

They're good vehicles. I can see why what's been said could give you pause, but from here on out they're all I'll want to drive.

In 1991, 1994 and 1997 Jeep strengthened up the bodies; the end result is a tougher, stronger body than you can shake a winch at.

If you are looking for truthfull information on your XJ/MJ you are now getting it at the right place. You will find that the concerns created by the un-knowing will be corrected here.

What a crock! You were fed a steaming pile and I wouldn't trust the source of mis-information.

I have beat the crap out of three Xj's now and I am amazed at the abuse these things will take. If you can keep the wheels on the ground (no roll overs) and keep it from rusting I see no problem with another 20 years.

Having said that, I would advise a roll cage as the top can collapse if you end up on the roof.

Good luck!

The only quirk regarding long life is the possibility of the floor rusting....pull up the carpet on the passenger side and check out the condition....sometimes water leaks in thru the cowl area or windhield into the floor pan....other than that enjoy....I love my Heeps....all 3 ....no make that 4....new addition....2 XJ's and 2 MJ's.

Ahhhaaahaaa...

Yea, my XJ broke in half after this pic



And the MJ rides only on the right front tire, and left rear tire, on level ground, after this flex.



:doh:

They're pretty tough. With chasis stiffeners, you will be fine. Now if you were hitten MOAB, Disney (serious rock crawlin') and such for 4 or 5 years, you might have some damage. But, then even with a frame, you would have similar problems.

The Unibody design is very stiff. So, most of the work in flexing, is done by the suspension. Not the body mounts, and frame. Look at the bed and cab lines on the MJ. A P-up with a frame would have some major twisting going on here.

What about these XJ's







look in here for a while;

http://www.naxja.org/forum/showthread.php?t=63901

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unibody on the Cherokee will with out a doubt ultimately fail even under normal use
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Poop just plain poop. I may be the king of easy does it. But I got more miles in the dirt them most of them yahoos got behind the wheel, including there peddle cars. Drive you Cherokee and let the arm chair offers kiss your rosy red.

Those body shop guys you spoke with...let me guess, they all drive fullsize trucks. I can't even tell you how many times I've had to listen to some local rednecks babble about ,"no frame-dat ting wont last..." blah blah blah....that's all it is. If all you're doing is driving it on the road and maybe a trail here and there but nothing hardcore, I'd save your money on anykind of stiffener. You won't be stressing/tweaking it enough to have any benefit.

HAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!! I have a 93 thats been more than four feet off the ground doing faster than should be done on and offroad on multiple occasions. Its been twisted, bumped, whoop de dood, scraped, high centered, run on, torqued, dropped, lifted, flexed to hell and back, and has been offroad in dire situations more than your average bear. All this, and I bought the bloody thing with more than 100 thousand miles worth of highway driving on it. I must have one of the rare exceptions to the rule, because I also closely inspect it regularly, and especially after offroad runs, and Ive yet to see even one of the spot welds pop.... And no, Im NOT gonna knock on any wood!

Like has been said, you have nothing to worry about. With normal use and occasional trail running that thing will last a long time. Yes, with years of hard wheeling, the body and frame will crack, but so will Wrangler's, CJ's, Toyota's, etc. I think the frame stiffeners are a good idea if you plan to wheel the rig now and then and keep it for a long time. The metal fatigue that eventually leads to cracks is accumulative. I've wheeled mine about as hard as anybody here, and had no cracks for many years, but all of a sudden I started getting cracks everywhere. But, that's wheeling it HARD over a long period of time. One reason the frame stiffeners work well is that they add some stiffness over a good length of the rig, between the front and rear suspension mounts. One cause of eventual cracks in heavily modified rigs is that some parts add rigidity in a localized area, adding stress to the area around it. It's better to add strength more consistantly over the length of the rig.

I don't agree with the comment about needing a cage because the roof will collapse. I've seen many rolled XJ's, in person and in pics, and the roof structure holds up very well in a rollover.

Goatman said:

I don't agree with the comment about needing a cage because the roof will collapse. I've seen many rolled XJ's, in person and in pics, and the roof structure holds up very well in a rollover.

Click to expand...

My first XJ (87 2.5L 4-spd) was one I bought as salvage after it had been rolled at 80k miles. My brother who has 20+ years autobody experience put on a new roof and windshield and I drove it another 120k miles. The only reason it is parked now is I was able to buy an 88 4.0L AW4 160k miles with a much nicer interior for cheap. The first one came from Wyoming where it had been really used, the second one came from California where it had been a daily driver.

I think unless you are doing extreme offroading or racing, I'd not worry about it.

This body style has been around a long time, and you see a lot of older XJ's and Wags on the road. I'm guessing the trouble spot would be the floors and then the rockers for the salt belt folks like me.