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Proper steps to determining suspension build question

925 Views 5 Replies 5 Participants Last post by  '05TJLWBRUBY
I'm trying to get a definitive step by step checklist of what order someone should install/[plan for components in doing the following suspension mods and trying to plan for the best combination of articulation and handling;

Build specs:
Three link mid arm setup with possible 1-2 inch stretch (a' la Melmo's axles minus stretch length)
AEV 3 inch progressive coils with 1inch bl/mml
Rear Outboarded shocks, raise front shock mounts if necessary
front swayloc, rear antirock
obviously adjustable track bars front and rear.
tummy tuck

So, with 3 inches of projected suspension lift, dual sway bars, and outboard shocks--what would be the plan of attack for putting it all together to get the useful flex to figure out what length shock to run (how tall of an outboarded mount to run)?

I want to do all of this in hopes of getting the most articulation-and determine if a highline would be necessary with the 35's with the 4 inches of total lift. I don't want to run more bumpstop than necessary just to compensate for lack of room. It just doesn't make sense to put all the right components together then have one severely limit overall performance or potential.

I'm guessing start with the control arms, then install the sway bars--then cycle the suspension to see how much flex the antirock and swalock limit you to so you can deduce shock length? I'm admittedly a bit lost, and have nothing but time-and a desire to learn and build this next project myself.
I'm not sure what components have to be installed in which order to determine the limitations of the others....It looks like pretty much everything except the shocks can be purchased in advance. If I'm going to go through all that trouble I want to have the best performing suspension possible, and I know it is going to be much more difficult than just bolting/welding stuff on.
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Just a few things to look for/at.

1) If you have proper length end links, the Currie Anti-Rock will not limit flex in any way.
2) As you flex the suspension, check the driveshafts for any binding.
3) On the rear, watch for the upper arms and truss hitting the tub and crossmember. The truss will hit the crossmember, and the arms will hit the tub where the back seat floorboard is.
4) If you don't mount the shocks far enough in, you will rub the shock body with the tire.
5) If you don't mount the shocks far enough out, the shock body will rub the frame/shock tower.
6) Don't just flex with the tires straight, flex with the steering wheel in every direction.

Ultimately, shocks would be the last item to measure and install. Some people want a lot of suspension drop while others want equal length up and down travel. Its going to come down to what you want. When you decide what you want, build it in that direction. Determine what up/down travel you want and then move/modify things to get to that point. If you have the capability, you can flex everything while on jack-stands, and really see whats going to happen.
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Phillip has some great advice. I'll add that with the anti-rocks setup properly they will not limit your travel in the least. Your projected build is almost identical to what I have currently and am working towards. I have been wanting the rear outboard for years now but in the beginning, was worried about my towing and the strength of the outboard mod. I've talked with Blaine a lot about this and am no longer worried. I WILL be doing this soon. In addition, front will get redone as well, with 3-link up there. That will be a while due to current extenuating circumstances unfortunately.

Relative to your build now, I do run front/rear bars. I actually have the dual-rate swayloc up front with the rear anti-rock. Without unhooking swaybars OR shocks, I could actually drop any corner and remove any one of my 3" AEV springs without issue. I run the Rancho 9000 adjustables that are built for the 4" lift. I THINK they're 10" fronts and 8" rears currently??? My suspension plans call for 12" travel split 50/50 meaning 6" up and 6" down with the outboard. It will be a bit of work to get that, but it will be well worth it.

You mention the possibility of high-lining your fenders for 35's with this setup. I will say YES, you will need to do something. I currently run 255/85's which are a true 33" tire. With my current setup now, I can stuff the tire without rubbing, BUT I'm VERY close-meaning less than 1/4" clearance at the fender. I actually had a couple screws on my inner fender that I somehow didn't think I'd hit, and actually sliced the tread blocks and broke the screw off at the fender. Actually the tire bent it flat to the fender, then I broke it off with pliars prior to removing that item from under the hood and eliminating the screws all together. Somehow I didn't check that spot close enough I guess. Live and learn. Point being, these are with 33's and front swayloc-and no, my shocks are not bottoming-but I am bumpstopped more than I'd really like to be. If I raise my front mount a hair and eliminate a little bumpstop, I'd be in the fender for sure. So, with that, I will say YES, you'll want some form of high-line setup to clear 35's for sure. I have a plan for this as well that will happen very soon I hope.

Depending on which TT setup you go with, may want to start there and get that done. It MAY effect placement of your upper link mounts on the frame depending on what you do with the rear-and front for that matter depending on what engine skid you run, and allow you to see where everything else fits when you setup the link mounts and cycle for clearance. That's not worded very well-hopefully you get the point.

With the rear anti-rock, you can do a couple things. If you set it up FIRST using a 44" bar with 20" bent arms, you can then use the arms to determine exactly how far you need to french into the frame for the outboard and see what needs to be done to clear the shocks inside the arm to make them fit. Like I said, I'm not at this point YET but am told by a very good source that it will work, just will be very tight. I've been running my rear anti-rock for years now and plan to do this soon with the outboard, using them as a guide to see just how far and how tight everything will be. The other option is to mount your shocks first where you want them, then fit the rear anti-rock in front of the axle, arms pointing back to the back of the Jeep and not worry about clearance at the outboard mod. Your choice. I've seen it both ways. Again, fitment of the TT first will help give clearance suggestions later as to what will fit where.

Are the springs/BL on currently now? If not, I'd do those first, followed by the TT/engine skid setup. You'll be at your basic lift height and have a good idea of stance before you start cutting. Swayloc can be done/installed now as well-just be sure to leave the links long for now till the rest of the arms/shocks are done and you know how much down travel you get so you avoid cutting the links too short. The BL will give a hair more clearance for when you drop the tank to do the rear outboard. You'll appreciate the little extra room. Go with the extended poly rear outboard kit-then cut down as needed for your desired shock height. Are you a TJ or LJ? If you're an LJ-the rear has PLENTY of room for the rear anti-rock and will be easy to install there. If a TJ, and you go behind the tank in the back, you'll have to run it without the outter DOM bar as there isn't enough clearance for that. Just use the tube to cut the mounts for the bushings-cut to size of course, then run the bar through on it's own. Tight, but it will fit.

Lots to think about and plan for. Will be a great handling/performing rig when you're done. Be sure to take lots of pics and post up here when you're done!!! :D You'll likely be done with your entire rig before I can start my 3-link so I'm itching to see how it goes for you! :lildevil:

Best of Luck,

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Trying to recap what I did and what I would do different. Not that I did anything correct, I just guessed as I went.

My thoughts

Control arms
Figure out where you want to mount them on the frame and on the axle. Cycle the suspension to see what your limits are. Adjust the mounts as necessary.
My findings, the limits of up travel were more dictated by hard frame and body interference with control arm and truss mounts than the body. I did all my testing without fenders on.

Shock Mounts and Length
From your control arm results, you can take measurements and start your search for the perfect shock.
My findings, I ordered shocks first and made things work with them.

Sway Bar
Sounds like what your picking won't be a limiting factor, like the others said.
My findings, make sure you figure out where you are going to mount them to the axle. It was one of my last steps and missed some contact areas.

Steering and Trackbar
Not sure on your plans here. But if you move the front axle around, there can be interference issues.
My findings, well I had to make some modifications to keep the drag link from hitting the diff cover. My front truss added 1/4 inch spacer to the diff cover, this caused some contact issues at full turn. Granted that could of been to close to begin with, but I did not do any testing with all things in place. Oops

Rear Shock mounts
Look at a TNT build on JF, they had a good way to figure out the mounting position for the frame. They used a square from the axle to the frame to determine the center of the shock mount.
My findings, I guessed at the shock tower, it worked out well. Don't forget to flex out full compression on one side and full droop on the other. I kinda forgot to take the angle change of the tires and needed wheel spacers to keep things from contacting.

Rear lower shock mounts
Many people swap the rear calipers and mounts.
My findings, I did not need to do that. I mounted the shock mounts high enough on each side to keep the lower mount out of the way of the caliper. Almost on top of the housing.

Rear Anti Rock
Make sure the bar and linkage does not hit the tire.
My findings, I left the rear anti rock bar above the rear tire, you can see it. I did this to keep the bar from hitting the tire. It is still in the center of the suspension travel, just at a higher angle.

Rear Truss
See where it is going to hit the upper cross member
My results, the RLCAs hit the frame at the same time the RUCAs hit the tub at the same time the truss hits the cross member.

Bump Stops
Figure out where they are going to go.
My findings, not sure I really needed air bumps. Thinking poly bumps would of been fine.

My thoughts, a decent set of tube fenders can accomplish what you need for up to 35s and 37 (for less money). If your going to 40s then they start to make sense to me.
My results, I have no more up travel to be had, so highlines would do me no good until I go to larger tires. I think I would have different issues with the larger axles needed to run the 40s any way.

Control arm mounts and travel will make most of your decisions.

So that kinda covers my steps and prob more of just my thoughts. How ever random they may of come out.
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Lots of good info in here.

For shocks I would look at the bilsteing 7100 series short bodies. You will be able to stuff a 14 inch shock into the same space as most 12's, they are fully rebuidable and tuneable, and they are actually pretty reasonably priced.

Would you consider the Bilstein over the Fox or King in the 12" remotes??? I worry about body length on the short spring setup with 3 link front setup (undecided on rear between 3 link and triangulated 4 link) want as much travel as possible with 50/50 split or as close to it. With 12" I can squeeze 6 up/down. With 14", wonder if 7 is possible for the split or 6 up/8 down. Interested to hear your thoughts on the shocks as I think it will both benefit this thread, and my decision as well. Any chance to save money is always good... :D

Happy New Years to you!

Best of Luck,

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