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.
After installing its three-link...
After installing its three-link front suspension, Poly Performance removed the rear Deaver leaf springs and went to work cutting off the factory spring hanger brackets. The factory brackets are basically just laminated sheetmetal and are prone to cracking and ripping off under very heavy use. A rough cut is made to get rid of the bulk of the factory brackets and reinforcements.
Next, the spot welds are drilled...
Next, the spot welds are drilled out and the plate holding the nutsert for the rear spring eye bolts are removed. Once you get to this step, load up the sanding disc in your grinder and make it all smooth so that the new Poly Performance brackets can be located off of existing Unitbody reference marks.
With the new brackets located,...
With the new brackets located, you can drill out the holes and attach the brackets to the floor and Unitbody with Grade 8 hardware. Note that the bracket ends have been sanded clean since our brackets will be welded on for additional strength. We really like the diamond-shaped ends, which will create additional weld area on the Unitbody and prevent cracking along the weld surface.
The finished product is miles...
The finished product is miles stronger than the factory sheetmetal brackets. The 3/16-inch steel not only makes for a more rigid suspension mounting point, but also serves to stiffen the floor and Unitbody. Plus, you can add Poly Performance's optional cage downtube tie in plates which give a much firmer cage tie-in than just bolting straight to the floor.
Once we dragged the vehicle...
Once we dragged the vehicle back home, we wrapped up the rear suspension rehash by replacing the stock rear bumpstops with some Daystar 1-inch-extended Polyurethane bumpstops (PN KJ09122BK). The new bumpstops should keep our 33x10.50R15 tires out of the fender flares nicely.
Since our rear Currie 9-inch...
Since our rear Currie 9-inch runs a 5x5.5 bolt pattern, we got a pair of Spidertrax wheel adapters (PN WHS-004) to convert our old Dana 30s bolt pattern from 5x4.5 to 5x5.5. In addition to allowing us to run our new 5x5.5 wheels until we could get our new front axle installed, the 1.25-inch-wide spacers also mimicked the overall width of our new front axle during suspension mock-up. Even though we had Currie build our new F9 front housing to factory specs, the Dana 44 spindles, hubs, and rotors we used on the Reid Racing conversion knuckles increased the overall track width by about 2-inches for a wide and stable stance.
We began our axle swap by...
We began our axle swap by drilling out our extended braided steel brake lines from our XJ Dana 30 calipers out to 7/16-inch. Had we thought of it, we could have bought later '76-up Chevy calipers and skipped this step, but we used the older ones with the larger banjo bolt. Then we removed the steering linkage, disconnected and removed the track bar, and yanked the old, bent Dana 30 for Pete "Jeep junk collector" Trasborg.
The Daystar EVS Stinger bumpstops...
The Daystar EVS Stinger bumpstops are half the price of conventional air bumps and come in two different lengths. We used a pair of the longer units (PN KU7109OBK) which have an 11.25-inch extended and 7-inch collapsed length. The shorter ones (PN KU71091BK) have an 8.25-inch extended and a 5.5-inch collapsed length. We also used the company's weld-on ends (PN KU71092) which makes for easy mounting in a TJ or XJ. The Daystar EVS Stingers can also be mounted inside traditional 2-inch air bump can mounts as well.
If you can cut and weld there's...
If you can cut and weld there's not much to the EVS Stinger installation. We used a reciprocating saw to remove the factory bumpstop tube from the coil bucket and then a sanding disc in our 4.5-inch angle grinder to smooth the mounting surface for welding. The factory coolant overflow bottle was right above the mount on the passenger-side, so we removed it to protect it from the heat of welding.
After fully welding the Daystar...
After fully welding the Daystar weld-on ends to the coil buckets, we inserted three of the blue EVS cushions inside the Stinger body and assembled them on the vehicle. If we need to, we'll swap in the firmer black cushions as necessary. The Stingers also come with a 2.5-inch spacer if you need to shorten the bumpstop travel, but we didn't need it in our application. The factory coil isolators slide right over the Stingers.
With the Stinger installation...
With the Stinger installation wrapped up, we swung the new Currie/Reid Racing Ford 9-inch onto the engine hoist and filled it up with 3 quarts of Currie's 9+ 85W-140 racing gear oil before positioning it under the vehicle. We attached the lower control arm mounts and track bar and set the axle roughly at ride height. After setting the caster to 6 degrees positive, we tack-welded the upper control arm bracket on at 0 degrees.
Although Deaver Suspension...
Although Deaver Suspension is well-known in the 4x4 industry for building high-quality leaf springs, not everybody realizes the company also offers coil springs. These progressive-rate Deaver coils (PN CSC08) offer a claimed 5.5 inches of lift on an XJ. Compared with the huge springs we had been running, the Deavers dropped the nose of our Cherokee down a full 2.5 inches with no loss in wheeltravel because we're still running the same shocks.
With the new Deaver coils...
With the new Deaver coils installed, we put the weight of the vehicle on the suspension and checked our caster angle again. We adjusted the upper control arm of the Poly Performance three-link to dial in the caster to exactly 6 degrees positive with the tires on the ground, then tightened down our suspension bolts and fully-welded the upper control arm mount.
Finally, we hooked up the...
Finally, we hooked up the Currie Currectlync steering linkage and Anti Rock sway bar from our previous buildup, set our toe measurement to 3/16-inch toe-in, and adjusted the drag link to center the steering wheel. The tie rod just makes contact with the centersection at full-lock when turning right, so we'll probably use our old trick of heating the pumpkin with a torch and hit the tie rod hard with a hammer to put a slight dent in the centersection for clearance. Check back next time, when we'll show you how to hook a driveshaft to one of these axles and wrap up the other stuff that keeps us from driving this Jeep