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RE Drop Brackets

Rubicon Express Control Arm Drop Brackets

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Installation  |  RE9905 Braces  |  Final Impressions  |  Control Arm Lengths

Background
Rubicon Express includes the RE9900 Drop Brackets and RE9905 Braces with their 5.5” Cherokee Extreme Duty lift, but they are also functional and highly recommended for other lifted Cherokees as well. After lifting any Cherokee more than about three inches, the control arms become steep enough to adversely affect the ride. Part of that rough ride is due to the steeper-than-stock angles on the front control arms. Rubicon Express offers a fix for this with their Control Arm Drop Brackets and Braces once the Jeep reaches about four inches of lift. Although you will lose some ground clearance right under your foot, the brackets put the upper and lower control arms at a more horizontal angle, like they were when stock. This change brings the ride and handling back to more acceptable levels, but also helps the front axle flex a bit better since the arms aren't already drooped several inches when sitting static.

After completing the RE6130 4.5" lift I experienced some excessive Death Wobble issues. With any lift that changes the geometry of the front suspension, I always recommend getting an alignment afterward. However, even with the alignment I still had a wickedly unsettling shimmy in the front end when I hit bumps in the roads at certain speeds. Additionally, with my 96 Cherokee at 4.5”, this meant that every time I hit a bump, the force of the bump pushed up into the control arm and into the frame before the sidewall if the tire deformed enough to climb over the bump. On the trail this can be rough, but on the highway the constant jarring makes for a really rough ride, and it’s not very forgiving on the vehicle either.

After searching for a few weeks, I found another Jeeper who was getting rid of the RE Drop Brackets and Braces for a great price. The only problem was that he was selling them without the hardware, but that’s fine because RE included the breakdown of the hardware kit in their online instructions. I completed the missing parts list using Grade 8 hardware, and stored the whole mess o’parts until I knew I had a solid weekend available to work.

Note the new, more horizontal position of the control arms. The long red line shows the original control arm angle.

The basic premise of the Drop Brackets really is a simple one. The Brackets fit into the stock control arm pockets and relocate the mounting points four inches lower. There are reinforcing plates that help prevent twisting, and use hard ABS spacers to take up the gaps left by the old control arms. Since the Drop Brackets lower the frame-side of the control arms to an almost stock geometry, the ride is incredibly better, and because the arms are now starting out in a static (flat) position they are able to droop farther without binding...this is also very good.

You can demonstrate this for yourself using your arm. Stretch your arm out in front of you with your hand in a fist, palm down. Imagine your fist is the solid front axle, and as you move it across in front of you, your fist has to travel over obstacles in the way. With your arm relatively flat, your hand (the axle) will move up and over obstacles easily. If you raise your elbow a few inches, obstacles impact your fist before you can climb them. Dropping your elbow is the goal of Drop Brackets.

RE9900 and RE9905 Installation
After storing the Brackets kit far longer than I needed to, I came up with a good timeframe for installation and had at it. RE has the installation instructions on their website and the pictures really helped remind me where the parts go. I highly recommend printing that page and referring to both of these writeups as you install your own Drop Brackets.

Drill the above hole out to 1/2"

Early on I realized I had a small problem that some of you may run into as well. The instructions call for a 1/2" hole in the upper control arm pocket; a part that normally fits a 7/16" bolt. While I have had friends do the installation with a stock-sized bolt in that location I decided to drill the hole...except I found you need a rather long 1/2" bit if you're going to make both holes from the outside. There wasn't enough room between the bellhousing and the frame for me to get it from inside the frame with my drill. A new drill bit added $12 to the project cost, but the reassurance of using the larger, stronger bolt is worth that. The bolts for the Upper Control Arms can be difficult until you recognize that they have a 'flag' attached to the head. Put a box wrench on the nut, and a socket w/extension into the framerail and around the head of the bolt. The bolt will start to turn until the flag hits the edge of the frame, at which point you can remove the nut. Take care not to drop the socket or the bolt into the frame void though as there isn't any good place to remove it. The infamous flag bolt. Discard this and use the supplied bolt

I started installation on the driver's side and thought I ran into a problem when trying to set the upper control arm (UCA) in place. As you can see, there was quite a bit of a gap between the UCA bushing and the new sidepieces for that arm. Trying to fit all the bolts in place for the UCA and the lower control arm (LCA) was a bit tight, making me wonder if my LCA pocket might be warped to the passenger side...

 
You can see from here that there is about 1/4" side-to-side. Click for larger images

It turns out that the gap is just fine. When everything gets tightened up the gap closes tremendously. This is evidence that it's VERY important to have all the bolts and holes in place before tightening anything.

Once you realize where all the parts go, installation is very straightforward. Having assisted on a couple installs previously, I’ve noticed that it's much easier to complete this installation on a fresh Cherokee. Unfortunately, the control arm pockets on the Cherokee are made of stamped sheetmetal, and ones that have seen a lot of 'wheeling often have loosened up a bit. This just makes installation that much tougher. Follow the instructions on RE's page to make sure you have everything in place before tightening anything down. This includes bolting up the RE9905 Braces if you are installing those as well.

When I originally ordered my RE6130 lift I upgraded to adjustable lower control arms, and that decision paid off nicely once I installed the Drop Brackets. The lower position meant the arms had to be shorter, so if the brackets are going on a previously-lifted Cherokee, you’ll probably need new lower and possibly even upper control arms depending on the height. I have previously published a chart showing typical control arm lengths, but feedback from other Jeepers indicates some of those measurements need review. I’ll update that and repost it if I get more info.

If you don't have adjustable control arms, caster can be changed by using a shim behind the pocket for the lower control arm. The heavy-gauge metal of the Drop Bracket (and the stock LCA pocket) is slotted, while there is a metal 'C' that wraps around the control arm bushing. On the back of that 'C' are two studs that poke through the back of the LCA pocket. By inserting the shim between the 'C' and the back of the pocket, the control arm is moved forward, tilting the pinion down slightly more.

Note on the RE9905 Braces
The RE9905 Braces aren't intended for the MJ Comanche, and on some early XJ Cherokees you will need to redrill the holes to line up with the crossmember. Typically this means the 1984-86 Cherokees, but as with all things Cherokee, check your Braces for proper fitment first and don’t be surprised if you have to reposition some of the mounting holes, especially on the older ones.

Use a floor jack to support the crossmember and remove one side at a time. Slide the Brace in between the frame and crossmember, install the new M10 bolts to hold it in place, and repeat for the other side. The bolts are an M10 (metric) with 1.50 pitch. Mine are overly long at 50mm but the excess length is no problem since they extend up into the frame void.

Side view of the installed Brace

Because I had previously installed (and removed) a t-case drop on Stinky, I didn't have to fight with replacing the studs. On stock Cherokees there are two bolts and two studs that hold the crossmember in place and often these are frozen with rust. The bolts are easy to remove, but folks seem to have a big problem pulling the studs. Hit that link for ideas on easy removal.

The braces don’t always fit flush to the framerails, so don’t be surprised if they start to deform when you tighten the four bolts on the back of the Drop Bracket itself. Once the front bolts are tight, you can tighten the crossmember bolts. I found that in many cases, tightening one set of bolts also helped loosen others, so it pays off to go over the bolts several times to make sure they are all torqued correctly.

Final Impressions

Installed shot of the Drop Brackets and Braces

The change was amazing. After getting all the parts in place and tightening them down, I took the Jeep for a drive around the block and while it didn’t feel entirely like stock, it was certainly an improved ride. There are some detractors who will tell you that the Drop Brackets reduce ground clearance and will hang the Jeep up. Looking at it, I don’t see it that way at all. The LCAs are tucked in near the tires, and the braces angle back toward the crossmember so if you set them on a rock you should slide off. When driving off-road you want to place your tire on the high spot anyway instead of straddling rocks so the control arms, Drop Brackets and Braces will be away from the rocks. The only change I want to make to the stock design will be to cut a portion off the rear of the Drop Bracket behind the LCA bolt to reduce the potential for that section dragging. Look at the top picture in this writeup to get an idea of where I plan to cut.

That’s it – although initially very complex-looking, the pieces come together nicely to enhance your Cherokee. Again, because they relocate the control arms approximately four inches lower, they aren’t recommended for use with a lift of less than four inches.

How long should the Control Arms be??
When you install the Drop Brackets on a lifted Jeep, the control arms will change the angle of the axle, and handling will be a problem. To get the correct geometry again, the length of the arms may need to change. Due to the differences in materials and overall lengths, the table below shows typical eye-to-eye control arm lengths for an XJ to bring the axle back to "normal" operation. Your mileage may vary...

RE9900 on Rubicon's Webstore

e-mail Jim
created: September 20, 2003