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Rubicon Express Full-Length Add-A-Leaf
Let me first say that it's amazing how much easier something like this is when you know what you're doing. It took me four evenings and most of a day to do the rears. Once I'd gotten the system down, it took only a few hours to do the fronts.
I also wanted to drill holes to mount those little Teflon pads to keep the leaves from rubbing. The pads weren't included from RE, but I got them from a local suspension shop for $0.65 each. My 1/8" pilot hole went through just fine, but bigger bits would just sit & spin when I used my hand drill at high speed. I finally bought a 1/2" cobalt drill bit and some cutting oil, repaired my dad's disfunctional drill press, and (on the advice of the suspension shop) set it up to spin at only 250 RPM. With a little bit of patience, that finally did the trick. This should ideally be done before you paint leaves, of course. Both of those first steps, which took me about two full evenings, are optional, but I wanted to do a professional job from the outset. Besides, we weren't scheduled to leave for our 4th of July wheeling trip for another few days yet...
My '95 had Teflon pads lining the clamps. I could have re-used them if I'd re-bent the clamps afterward, but I would have had to dismantle the entire spring pack to get them off the clamps, then reassemble the pack to bend the clamps straight, then disassemble it again to put the new leaf in. This seemed like overkill to me, so I just cut them off with a screwdriver and hammer. Besides, they won't fit on my new U-shaped configuration anyway. Don't just burn them off -- it's rumored that burning Teflon is toxic.
Once the clamps are straight, it's time to unfasten the spring mount U-bolts and prop the axle up out of the way. This will be easier if you spray all affected bolts with PB Blaster, Liquid Wrench, WD-40, or similar for several days before you begin wrenching. If you want to drop the shackle end of the springs, you'll want to disconnect the axle before that. It's easier to reassemble the leaf pack after you bolt the main leaf back into the shackle first. (This is a good time to reverse the lower shackle bolt so that the nut, not the bolt head, is closest to the gas tank.) Be sure to clamp the leaf pack together before you unscrew the center pin, otherwise all the lower leaves will fall onto your hand when the nut comes free. If you've got the time, this would be a good time to coat your leaves with POR-15 or at least a fresh coat of paint to ward off rust.
According to the factory service manual, the U-bolts should be torqued to 52 ft-lbs, and the shackle bolts should be torqued to 80 ft-lbs. After a few days of driving, you should double check all your nuts to make sure they're tight. I'll reiterate what the FSM states in bold print: don't tighten the spring & shackle bolts until the Jeep is back on the ground and resting on all fours. If you tighten them down while the tires are hanging unsprung, you'll hear lots of squeaking from the bushings whenever the springs have to flex upwards.
By measuring the front wheel height during the photo session on the right and then doing a little math, I figure the new suspension would have an RTI of around 450 on a 20-degree ramp. Since I lost an inch of travel at each end, the original suspension (sans sway bar and rear track bar) probably ramped around 500-520. Here's the measurements before the lift and a few days after installation:
About three months after installing the leaves, I finally broke down and got longer rear shocks. The ride with the stock shocks was ridiculously harsh over speed bumps and such because the shocks weren't allowing the normal bouncing motion. I disconnected the bottom of the rear shocks, maxxed out my articulation, and measured the length I needed for the new shocks. I found that the most length was required not when cross-axled, but when the rear end was hanging from my Hi-Lift jack with both wheels in the air. The minimum length required (with no load, mind you) was 15". The maximum length was 20". I know the rear end sits quite a bit lower when heavily-loaded, so I chose 13.5" and 20" as my required lengths. For reference, the stock shocks I removed stretched from 12" to 18.25". (The stock front shocks are 17" to 24.5".) Since I didn't know what vehicle might have come with shocks of this length, we spent some time hunting through the shock shelves at Parts America looking for something that would fit. I finally came away with two Monroe Gas-Matic Plus 37042MP's for $26 apiece. They stretched from 13.5" to 21", which should work well. When I went to install them, I ran into a couple problems. First, the upper shock eye on a stock YJ shock doesn't have a metal sleeve inside the bushing. Rather than the 1/2" eye/bushing that seems to be standard, the YJ upper mount uses a 5/8" mounting pin and a harder rubber bushing with no sleeve. In order to get the new shocks to fit, I had to cut the metal sleeve into pieces with a hacksaw and pull it out with vice grips and PB Blaster. Of course, this caused the rubber bushing to shrink, leaving me with only a 3/8" opening. To get it on the 5/8" pin, I had to file the ends of the pin down so they had a slight angle, and then grease the pin and press the shock onto the pin with a C-clamp. Kind of a pain, but it worked. When I then went to mount the bottom eye, I found that the sleeve in the new shock was too wide for the mounting bracket. I had to cut off 1/16" or so from each end of the sleeve to make it fit. This wasn't nearly as much trouble as the upper mount. The final result gives a much smoother ride (according to my wife, who never rode in it during the week between disconnecting the old shocks and finishing installing the new ones). It also gives better rear wheel travel, which should help my axle articulation. I've yet to measure it with the new shocks, but I'll update this page when I do. The rear brake hose is now a little snug under full droop, but it's not the only limiting factor, so I think I can live with it until I go SOA and install really long brake lines. Back to Obi-Wan's Popular Mods pagelast updated 26 Oct 98 Obi-Wan (obiwan@jedi.com) |
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