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Since I decided to install a set of DJM control arms myself, and it requires a complete front suspension disassembly, I figured that I might as well document the process.
The DJM arms provide a true 2" drop by lowering the spring pockets. They also add the benefit of urethane bushings. And, according to DJM, dropping a Lightning more than 2" requires the upper arms to maintain proper ball joint angles.
The DJM arms are 4 lbs heavier than stock (DJM lower 22 vs. stock 21, DJM upper 8 vs. stock 5). With the spindle/rotor (50 lbs), caliper (12 lbs), and wheel (74 lbs), the unsprung weight on each wheel is a whopping 166 lbs. Suggested tools:
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Prepping the bushings and grease fittings is especially important -- read the instructions. The DJM arms use a metal sleeve-in-metal sleeve arrangement for the lower arms (supposed to prevent urethane sqeaking). You need to jack up the front about as high as you can get it and place it on jackstands. Remove the wheel, brake caliper, the anti-sway bar links (14mm), ABS sensor (8mm), and shocks (bottom 13mm/1/2", top 14mm). Note for Hotchkis owners: Other have reported than the front anti-sway bar freezes up. After just a little over a year and 10,000 miles, mine was so stuck in the bushings that it tool both arms just to move it. So I gave it a good cleaning and lubed it with the Prothane lube that comes with the DJM arms. If you have cam bolts, take a Sharpie and mark the top so that you can be close on the alignment with the new arms. Then remove the steering arms. You have to use a pickle fork, ball joint press, or smack the crap out of the bolt to get it up and out of the spindle. Then put a jack under the lower arm between the shock stays and the spindle. Provide just enough upward pressure to keep the spring pressurized. Remove the cotter pins and loosen (but not remove) the upper and lower ball joint nuts. Try to make the upper arm budge by smacking upwards with a rubber mallet or deadblow hammer. Because I didn't have a pickle fork, I ended up taking off the frame bolts and then letting the upper arm come back over the spindle so I could get a good shot at the ball joint bolt. A shot to the end of the bolt with a 2 lb ball peen hammer finally broke it free. Since the DJM arms come with new ball joints, I didn't worry about damaging the stock ball joint bolts. The upper arm frame bolts have a 21mm head and 22mm nut. |
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With the upper arm off, you can then lower the jack slowly until the spring falls out. Then remove the lower arm. The frame bolts require 21MM and 15/16 (or metric equivalent) deepwell sockets. A breaker bar is helpful here. Anytime I work near the frame, I start reassembly by stripping off that sticky protectant that Ford puts on the frame and recoating with real undercoating. It does add some drying time to the process, though. |
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Now to put everything back together again. It's best to prelube the sleeves. I also prelubed the ball joints. It's also a good idea to use a tap to chase all of the threaded holes -- the powder coating gets in there. |
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Remember to return the cam bolts to the same position as before (turn cam bolts to adjust, then tighten the nut while holding that position). Note the caliper hung from a coat hangar and the rubber gasket on the jack saddle to prevent scarring the finish on the arm. Also, you will need to rig up something to hold the ABS sensor cable. In the shot below, you can see that I just ran a wrap of electrical taps around one of the upper arm tubes and used a high-strength zip tie. |
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| Pump grease into the zerks and head off to the alignment shop. |
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the finished product:
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  Note:
although the anti-sway bar end links look lined up in the above photo
(at an unnatural extension), they are actually not. The
photo to the left shows the end links at normal ride height. The
photo to the right shows how the paint has been rubbed off and the
bushings damaged by the misalignment. |
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results: On the first try, because I wanted to limit the front drop to 2-2.5", I used the stock top spring isolators instead of the much thinner Hotchkis isolators. Even with the thicker spring pad, that dropped me to a whopping 15.5" - 3.5" less than stock. Therefore, the addition of the DJM arms, even after adding in the increased thickness of the of stock spring pad, caused a 2.5" net drop over the same springs with the stock arms (would have been 3" or more if I reused the thin Hotchkis pad).
This is too low for my sensibilities. The valance wouldn't last a week, an aftermarket heat exchanger would be suicidal, and the bump steer would presumably be unacceptable. |
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So I installed some Ruslow 1,100 lb springs (shown coated in silver appliance epoxy below next the to black Hotchkis coils). Although the Ruslows are about the same height unloaded, the higher spring rate brought the height up over an inch. |
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I'm now back to 17.5 -- almost where I started before the DJM arm swap (17.75-18). I will wait for the suspension to settle in. Then, if needed to get 17" on the money, I will trim a little off of the bottom of the coils. One advantage of this approach will be to get the stance even from side to side. The passenger side has always sat a little higher -- if anything, I want it the other way around. The saga continues . . . |
Replacement
is just the reverse. Mount the lower control arm to the frame,
jack it up until the spring is seated, and install the upper control arm
and everything else. 
Finally,
the DJM arms expect the stock brake lines, but I have stainless lines.
So I used (2) 3/4" long 1/4" bolts and lockwashers to fasten a pair of
insulated hose clamps to the arms. The brake line rides in a
sleeve made from a short length of transmission fluid hose.
Mike
Dunn came up with this ingenious solution.
Next,
to try to bring it back up, I removed the stock rubber
