So, to be clear, does the kit come with full leaf-springs or just an add-a-leaf spring?
As for your other questions, it all depends on your 'cost vs performance' argument. If you're looking to do it on the cheap, you don't have to purchase anything extra:
In a perfect world, you want your trackbar and drag-link to run parallel with each other, otherwise on-road handling and comfort will start to suffer (things like bumpsteer, wandering under braking, etc). Once you lift a cherokee, these two components will sometimes be out of line with each other, so there are ways to get them back to being parallel.
The drop pitman arm is one option. The pitman arm bolts to the steering box and the top end of the drag-link. A longer pitman arm will drop the top end of the drag-link to a lower position which can bring it more into line with the trackbar. Personally I would go ahead with the lift first, and check after to see if a drop pitman arm is necessary in your case. If it is, a pitman arm from a Jeep Grand Cherokee (ZJ) 93-98 can be used for a 1" drop.
The trackbar centre's the front axle underneath the Jeep. Lifting the cherokee without doing anything to the trackbar will result in the front axle being off-centre, sticking out more to the driver's side. This isn't a huuuge problem but it can cause the notorious 'death wobble' problem. There is a simple fix for this without having to drop a couple hundred on an adjustable-length trackbar, and that is to drill a new mounting hole on the axle end, about 3/4" more towards the driver's side from the stock bolt mounting location. There are a few write-ups on the internet, just google em.
As for sway bar, you don't need to change it at all. What DOES become necessary is longer sway-bar links, which you stated was included in the kit, so you'll be fine there.
Personally I ran a 6" lift in my old cherokee, had the trackbar bolt re-drilled on the axle end (started getting death wobble and this fixed it), removed my rear swaybar completely (its not necessary, but the front one certainly is for driving around town), stuck with my stock pitman arm, didn't need a transfer case drop of any kind (make sure your driveshaft u-joints are good, and your pinion angles are set properly with axle shims if necessary), and even ran fine with stock length front sway-bar links (although they did sit pretty close to the coil springs though).
And this was my daily driver, it felt fine driving it around town, no driveline vibes, and when I got my first wobble I re-drilled the trackbar bolt location and that fixed it.
Topic: cherokee xj 98 (Read 4151 times)