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Introduction:
Jeep springs for 6” of lift on a Bronco II (a.k.a. how I learned to stop worrying and learned to love Jeep parts) – Ryan Costello (ryan or ryan_nwu depending on the board) I got my Bronco II in the summer of 2001 and at the time I knew pretty little about TTB other than it being some form of early Ford IFS. I had it for a little less than a year, and by that time decided that it was time for some 33s so I installed a 6” Skyjacker Class II and a set of 33x14.5 Swamper SSRs (have these tires really lasted me THREE years? Yes, and though they have a noticeable wear that is still three years for a mud tire – lets see any other brand go that long). I wheeled the 6” Skyjacker coils for about another two years, but started getting annoyed. The Skyjacker springs were adequate to push my truck fairly far, but they did not compress anywhere near as much as I would have liked. When climbing over anything about 15” tall with one wheel you can really feel the coil binding and the instability of the truck. In the second picture you can really see how small this obstacle really is – I would say that the rock in the picture is only 20-24” tall. The only things limiting my uptravel in this situation were the coils – nothing else was rubbing, and I don’t have extended bumpstops installed. At this point I knew I had to do something if I expected to wheel my truck the way I wanted to wheel it. Thankfully someone else (who shall remain nameless) was working on his idea to run softer springs on the front of his B2. He called his idea “suicide springs, and it worked well on his truck with a James Duff 3” lift and I started working on collecting my parts for my own swap. At the same time I did my D35/8.8 swap since I was going to have the suspension off anyways. The difference between the two is that I was going with a jeep spring that would give me 6” of lift to go with my Skyjacker hardware. Parts List: Here’s a list of all the parts I gathered for my conversion. I got most of them from someone who had tried it and didn’t like the results: XJ lift springs – 22” free length, 11 free coils, and 240 #/in spring rate Parts for new springs pads to mount them to the axle in the Jeep style (coil isolators, and other misc. parts) Duff old style dual shock hoop (this actually was the hardest thing for me to get – I waited for quite some time to get it) 2 Rancho RSX shocks (31” expanded, 20” compressed) 2 Rancho RS5000 shocks (29” expanded, 18” compressed) *These shocks are the ones that I used based on how my truck acted. You should measure for your own shocks if you’re performing this modification Rubicon Express adjustable spring mounts (for the 8.8 conversion) Skyjacker coils vs XJ coils: Here you can get a sense of how different these coils are – the bottom two are the Skyjacker coils I removed, and the top ones are the XJ coils. Notice how much thinner the wire is on the XJ coils – it’s quite dramatic Installation: I put my springs in along with a new front axle, so it was all pretty straightforward. Drop everything and then install new coils (if you need help with that, this might not be a modification for you). I was left with this: Note: the isolator in this picture is upside down. I was trying stuff out and this is ultimately NOT the way I would do it. The next picture is of the suspension hanging freely:
Next I had to measure for my shocks. I made the lower shock mounts out of ¼” plate (you can obviously go thinner – this is what I had available) and mounted them on the former sway bar mounting spot. I had to mount my shocks inboard (toward the diff) because mounted at the sway bar mounting point and outboard from it they had a severe rub on the steering links. I got the following measurements for what shocks I would need in a perfect world: Front shock position (30 ½” extended): Rear shock position (27” extended): This created a problem for me – I needed to find a shock with lots of travel, but in pretty odd measurement sizes. The rear shock wasn’t terribly difficult to find, but the front shock was pretty horrible. I ended up compromising and choosing something with a long stroke, but not necessarily the length for what I was needed. Something else to note is that with the coils in I got binding at about 34” extended length for the shock. I think that there could be situations where I would use all of this travel, but doubt that it would be necessary under normal conditions, and would require the use of a custom shock. Regardless, you have to measure the shocks after putting the springs in, don’t buy them beforehand based on how you expect the truck to handle. I settled on the rancho shocks that best fit my application. I chose Rancho essentially just because I had the catalogs handy at the parts store, and so I could get them next day as well. The RSX shocks are intended for an F250, a positive for me because they are, at least theoretically, valved for the specific application, and I needed all the dampening I could get. Shock Mounting: Using Jeep springs basically requires using a dual shock setup in front. Based on other reports, using two shocks behind the coil will not dampen the sway as effectively as they do with one in front and one behind the coil. Mounting the shocks proved to be a system of trial and error. With this much coil there’s no way to mount them in the original sway bar position – the coil itself interferes. I was left with two options – either mount the shock on the inboard or outboard from the sway bar mounting point. Positioning it outboard would have left me with a really massive interference with the steering links, so the only place I had left was inboard of the sway bar mounting points. Pictures describe it best: Side view with the suspension hanging: Tech. Page updated by: Ben Hart |
While wheeling in the northeast I took a few pictures: 
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