Project JR 2.0: 1999 Jeep Cherokee SportPosted in Project Vehicles on August 1, 2010 Comment (0)
We're really cranking along on our '99 XJ project revamp. You may recall that in Part I we ditched the old-school long-arm suspension in favor of a Poly Performance three-link long-arm with a new track bar setup. In Part II we built up a new front Currie F9 9-inch with a high-pinion centersection and Reid Racing knuckles, which allowed old-style Dana 44 outers. Now here's the front axle installation and suspension wrap-up that we promised you last time around.
For starters, the Currie F9 housing with its angular plate-steel construction is much larger than the little Dana 30 it replaced. However, it does look like everything is going to clear at full-stuff. Currie installed its heavy-duty suspension brackets, so we just needed to drill out the track bar mount to fit the larger 9/16-inch bolt of Poly Performance track bar, set the caster, and weld on the special upper control arm mount for the Poly Performance three-link. We also drilled our brake hose fittings to match the larger 7/16-inch caliper banjo bolts of our Chevy Dana 44 calipers. We'll have to make some exhaust modifications to the downpipe and order up a new front driveshaft, but we'll address those issues next time.
Suspension-wise, we were looking for a few upgrades over our old setup. For starters, the new Poly Performance lower control arms are bent up and angled inwards for trail and tire clearance. Plus, the three-link offers more flex, less binding, and more clearance above the pumpkin, since there's no driver-side upper control arm.
Before bringing Project JR home from Poly Performance's shop up in San Louis Obispo, California, we had the guys install the company's very heavy-duty rear spring hanger brackets. The installation is intense, but if you've got a cutoff tool and a drill to remove the spot welds, it's doable for the average enthusiast. The Poly Performance XJ spring hanger brackets replace the stock XJ hangers which can crack under hard use. The new brackets are bolted in place and can be welded for additional strength. They can also incorporate an optional rollcage downtube plate to tie the chassis together and further stiffen the XJ Unitbody platform.
We also wanted to ditch the insanely tall coils that we used to run on this Jeep. They were part of our old suspension kit, and despite their claimed 6-inch lift, delivered more like 8 inches up front. We cured this with a set of progressive-rate Deaver 5.5-inch lift coils. These Deaver XJ coils are the same ones used by many Jeepspeed competitors, so we're sure they'll stand up to any abuse that we can dish out. Plus, we're already running some nice, soft 4-inch Deaver leaf springs out back. Leave it to Deaver.
Another suspension item we needed to address was our bumpstops. Up front, we're running 10-inch-travel Bilstein 5150 shocks. It's all the shock shaft that you can squeeze under a Cherokee without modifying the factory mounts. With our stem conversion uppers, our new Deaver coils just barely unseat from the buckets when the suspension drops out. But we wanted to soften the harsh impact, as the bumpstops make contact at full-stuff. Rather than go for expensive and overkill air bumps, we tapped Daystar for a pair of its new EVS Stinger bumpstops. Instead of using a Nitrogen charge to provide dampening, the Stingers use compressible EVS cushions. You can mix-and-match between the softer blue and firmer black cushions to create the right bumpstop dampening for your application. And out back, our old suspension used raised bumpstop pads off the rear spring perches which were really too short. Finally, we swapped to some standard rear spring perches and swapped our stock bumpstops out for a set of Daystar 1-inch drop polyurethane bumpstops.
Enjoy the suspension wrap-up and axle installation this month. And be sure to check back next month, when we'll clue you in to those new wheels and tires, spin wrenches under the hood, and make a bunch of little upgrades to get this vehicle roadworthy after its long hibernation.