Possibly moving from a ZJ to an FJ (1 Viewer)

[Darwood]

For a rock crawler I would rather have a ZJ. The size and the 5 link suspension easily out performs the 80 series. I agree with most of what Nay says, but the ZJ will perform better than an XJ off road due to the rear coil suspension. Also the 5.2l (318 v8) option is nice.

Now having said that I used to have a 93 ZJ and I love the 80 series. I was never really in love with the ZJ. UniBody, vauge steering, questionable reliability where all things I didn't like. Mine never had a major problem in the 115k miles that I knew it but the tranny was starting to randomly drop a quart of fluid every once and a while which was cause for concerning.

If rock crawling is a major concern I would keep the ZJ. It flexes better and is smaller. If you want something that is built better I would get the 80.

 

[Nay]

Nay, that's not really true. There just aren't any "off the shelf" disconnects available. And that's mainly based on the swaybars not limiting flex, but just pulling the body over. The rear disconnects are absolutely stupid easy to make and the fronts are only slightly more work but both front and rears could be fabricated for less than $100

I'd like to see pics of this - disconnecting the swaybars opens up a world of longer shocks and spaced down suspension travel if you are willing to redesign the front end. Nonetheless, the question is whether they don't limit flex because the radius arms are so restrictive and the shocks are short. When a stock shock has 10" of travel, and a 6" lifted shock has 11" of travel...I think we do have some major restriction. Back to the Jeep comparison: the stock shock is 7" of travel and on a 6" lift people use 11" travel - 14" travel - the gains in lift height are proportionate to the gains in suspension travel (with a little work of course ).

This is where the comparo gets dicey. If it's stock arm to stock arm then the 80 gets the nod. True you can get a cheaper set of long arms for the xj but I don't think you'll get anymore from the front of the xj than you'd get with the slee arms (+12"). And as you mention, that's not always a bad thing when having a dual purpose rig.

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That's a standard XJ build with long arms - you don't need long arms for this kind of travel because the Jeep bushings are big and johnny joint adjustable arms are readily available...the long arms are for the angles, and the off the shelf stuff comes with the serious clearance compromise of 36" arms. The best setup I've seen used a mid-length lower arm of about 20 inches with the axle mount flush with the tube - the upper was in the stock frame position as a 3-link, johnny joints all the way around. That would be an awesome setup on an 80 to set the front end free. Still, I have yet to see a picture of an 80 showing all that much front flex with stock mounted arms...small bushings can only deflect so much.

Try this one with a rear coil conversion and unrestricted flex (this does come with some major downsides depending on the arm design...hard to get a good roll axis on those conversions):

Again, how much do you spend to re-gear/ARB lock an xj? If it gets close to or in any way offsets the expense of a s/c for the 80 then it's a wash. I never had a v8 xj drop me

You could probably get a nice moderate mileage late model XJ for $5K and you just buy new axles front and rear for about $6K including gears and lockers (if you do it smart...you can spend more than that for sure). Just the 80 will run you that much. Can SC either one if you want to.

It's true that the 35's will fit the 80 with very little work compared to doing it on a xj. It'd be tough call though to compare both the 80 and xj on 33's on a trail. I have seen xj's break axles on trails though so that is a real concern. My main isssue is how ugly the xj is...

On that I will agree - XJ's tend to get pretty ugly to make them big...36's fit nicely on an 80 without much lift, and that is the #1 advantage that helps offset the huge size of the 80 for serious wheeling. On the 80, you can easily keep lift low and strap on some serious rubber...you have to cut the crap out of an XJ or ZJ to accomplish that. And we know that it is all about tire size

Nay

 

[cruiserdan]

It doesn't matter how well they wheel. I don't like them... It's a Jeep thing I guess.....

 

[Nay]

I agree with most of what Nay says, but the ZJ will perform better than an XJ off road due to the rear coil suspension.

I actually disagree with this, and it's kind of irrelevant for this forum unless you are looking beyond bolt on solutions, but factory quad coil suspensions tend to be quirky for rock crawling. They often suffer from wheel jack under torque, among other things, especially as lift increases. The restrictiveness of the 80 (connected swaybars, small front bushings) is actually not a bad thing for moderate use (as in not extreme), because it seems to avoid some of the issues of a longer travel supsension that moves completely freely across the entire range of shock travel (such as unloading the front end on steep obstacles climbs). The issue is when you get to the point where you simply need the extra travel and you are still foolish enough to use your daily driver for that purpose .

The XJ rear leaf springs are spring-over from the factory and can use the entire length of an 11" travel shock when used with a block and traction arm to eliminate spring wrap. They offer a huge amount of stability (and load bearing) in combination with the front five link that is incredibly driver friendly while still allowing a long travel suspension.

ZJ's are, in my experience driving them, absolutely soul-less. Nobody loves a ZJ or a WJ or a KJ, and the reliabilty knock is just a way to express that. XJ's are in many ways disasters (see second row of seats), but people absolutely love them. Jeep is dead.

Nay

 

[slomatt]

Excellent points!

The ZJ's size and weight (3900lbs stock) are big benefits in tight trails, which are what we often run. I am very aware of the 80's increased girth, especially since most of the people I offroad with have 8-9k winches which could have a difficult time extracting a hard-stuck 80 (is that blasphemy on here to insinuate that a 80 could get stuck? ).

The 80 is appealing because of its front and rear solid axles, strong running gear, nicer accomodations, and available f/r lockers. With an automatic I'm not that concerned with the difference in t/c ratios (2.7:1 vs 2.5:1 I belive).

With my ZJ I was able to simply swap the front springs to the rear and add 3" front lift springs (along with some other supporting hardware) to clear 33" tires with some major trimming. The stock open axles/diffs can handle this tire size, but as with all XJs and ZJs once you get above 33" tires the stock axles are a bit of an issue.

As Nay mentioned installing new axles is not a huge deal. Swapping in a HP30 front and a Ford 8.8 rear with 4.56 gears and lockers can be done for under $3k. Many people have also swapped in full-width axles.

My decision has been do I spend that $3k to re-axle, lock the rear and cross my fingers, or sell the ZJ and buy an 80. This discussion about the 80's rock-crawling abilities has been very informative, thanks!

Width is an issue (scrapes are not from my truck):
http://www.blankwhitepage.com/gallery/dusy20040917/IMG_3276

And rocks do get in the way:
http://www.blankwhitepage.com/gallery/dusy20040917/IMG_3287

- Matt

 

[Darwood]

I actually disagree with this....

You seem to have more experience with the ZJ vs XJ issue so I'll concede that you are probably right. I just know from my experience that my ZJ was a crazy flexy machine with 4.5 inches of lift and 31x10.50 15's. I had the '93 249 quardatrack transfercase which meant that it did not lock in the center. Even in 4low it was still only a viscous coupled center differential at best. In other words if I lifted a tire I wasn't going to go forward. Fortunately lifting a tire was a rare occurrence.

Add that I would rather have a ZJ in the rocks because it doesn't really matter if you smash it. After all it's only a ZJ not an 80.

 

[landtank]

back to the qustion, I get 16 mpg all the time on the highway at speeds of 75 with my modified 80 up here in New England where it's not all that flat.

4" lift, 35s, 4.88s, ARB w/winch, Kaymar and sliders