Rubicon Express Extreme Duty 5.5” TJ Lift Kit
By Chad Crowell

Rubicon Express Extreme TJ Kit!


Testing out the new kit in the Sierras.Back in May, 1998, three weeks after I bought my brand new TJ, I found myself explaining to my girlfriend why I needed this $1600, 4.5” lift kit when there were other kits out there for half the price. “It’s got everything,” I told her, “so I don’t have to buy other parts to make it work better later.”

Now as I stare at the $2500 worth of boxes in my garage, I find myself recoiling as she repeats those words to me, wondering why I spent more money if the first lift had everything I needed. Well, in not so many words…here’s what I told her:

When the TJ first debuted, lift kits came out in all shapes and sizes. Some had Acme joints, some had heim joints, some used 4” drop brackets on the control arm mounts, and some used double track bars.   Some of these are still around, and some aren’t. One thing is for sure, a super-flexible lift can be installed on a TJ and still leave you with a respectable road ride. That’s what I wanted, that’s what I got.

I bought a Rubicon Express 4.5” TJ kit back when the cartridge joints were a brand new idea. As a matter of fact, I think I even had the first kit that used the cartridge joints on the lower arms. My uppers still had heims. Let me tell you, this kit has worked GREAT! The road ride is nice, stable, and not too rough. And, off-road, it's amazing.

After two years of everyday driving and regular wheeling, there has been some wear and tear. My heim joints have worn out, leaving me with a creaky, squeaky Jeep. The rubber bushings on the arms have also worn somewhat from all the use I have given them.  I was basically at a point where I was ready to replace all my upper arms, and replace the bushings in the lower and track arm.

Then I began hearing about the new long arm TJ lift from…who else…Rubicon Express.   After reading a few short articles on this lift, I knew I had to have one. I originally planned to keep my springs and other hardware, and just add the new skidplate and arms, but decided in the long run it would, again, be better to get the kit that has everything so I don’t have to buy other parts to make it work better later. Déjà vu, no?

The truth is, you can upgrade your current 3” or 4.5” kit to the long arm kit without buying other parts later…you’ll reap all the benefits of the full kit, but won’t sit up so high. The full kit, with its 5.5” springs, allows fitment of 35” tires without a body lift.   From what I hear, 36’s will be no problem either. And that is my plan once my 35” General Grabbers wear out.

Spring height difference is clear.

So I bought the kit, in order to avoid replacing the arms in my old lift. Spend money to save money as they say.   What will this kit gain me? The whole theory of the long arm kit…and from all indications the theory works, is to decrease the angle at which your control arms live.   Look at a new TJ.   Its control arms are almost perfectly horizontal.   This allows the front axle to move up and back under compression, as when hitting a bump in the road. This is one reason for the TJ’s great ride quality in stock form. When TJ’s are lifted using the stock suspension mounting points, the control arm angles are increased, which causes the front axle to have to move forward and up causing the ride quality to be somewhat harsh. Another negative aspect of this modified factory geometry is that the wheelbase is shorter than delivered from factory. This causes two things: squirrelly handling and tires that are noticeably not centered in the wheel wells at ride height (this is the reason lifted TJ’s require a body lift to run 35’s.)

Installing a standard TJ lift, like the Rubicon Express 4.5” kit, adds control arms that are slightly longer, and springs that are much taller. The effect is that the axle sits 4.5” lower from the frame, and those control arms are now at an almost 30° angle. This, combined with a stiffer spring rate, makes it much tougher for the axle to react to bumps as it was designed to do.   Now don’t get me wrong…I said in my original 4.5” article that the road ride was very good after the springs broke in, and I still think that to this day, but riding in a stock TJ once in a while reminds me of how nice the ride COULD be.

Rubicon Express

The RE long arm kit improves these angles by doing something never before done on a TJ…using 36” long control arms! The arms bolt to the axle in the same location, but your frame mounts will need to be cut off.   The arms bolt to a new transfer case crossmember that replaces your stock one (or in my case the Metcalf Motorsports flat skid). This allows the use of the long arms, and decreases the angle at which they live.   Even with the 5.5” springs, they are at a less steep angle, and with the 4.5” springs, they are even better…close to stock. Word is, even with the tall springs, the road ride is as good as stock. We will see.

What about off-road performance? Well, RE does focus the benefits of this kit on the street, but they were also quick to point out that off-road, the Jeep will feel more balanced and stable, and respond better to situations where the tire may stick up against a vertical rock.   I knew exactly what he was talking about…many times I had approached an obstacle only to find that when gas was applied, the entire Jeep lifted, wanting to climb, but the tire on the rock moved down and back instead of up and over as the spring stretched and unseated.

This brings up another issue: TJ tire pick. I have done this twice in my TJ…and really don’t ever care to do it again.   With a tall lift, turning left slightly and punching the gas can cause the driver side front tire to come off the ground. Pretty scary if you aren’t expecting it. Evidently, this new kit eliminates that “feature” altogether.

Drawbacks?   I can only think of two…being that the arms attach to the skidplate, any work on the Jeep that requires removal of that plate (clutch, tranny work) will also require removing the axles, or at least disconnecting the arms from the plate and supporting the vehicle on tall jack stands. At 38,000 miles, I think a clutch is still at least a year off for me, and with any luck, I won’t need any other underbody work. The only other modification I can think of at this time is adding low gears to my transfer case. And that, in my opinion, is worth the trouble. If you don’t work on your own TJ, be aware that there will be extra shop time needed because of this characteristic.

Also, once you install this kit, there is (almost) no going back. New frame brackets for the control arms would have to be welded on, as they must be cut off during installation. If that doesn’t scare you away, then you should consider yourself a prime candidate for the RE long arm kit.


Intro | The Plan | Skidplate | Rear End | Front End | Impressions


Rubicon Express
Phone: (916) 858-8575
Fax: (916) 858-1963
Email: sales@rubiconexpress.com
3315 Monier Circle
Rancho Cordova, CA 95742

Tom Wood's Custom Drive Shafts
Phone: (877) 4xSHAFT
Fax: (877) 4xJOINT
Email: sales@rubiconexpress.com
306 East 31 Street
Ogden, UT 84401
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Phone: (714) 528-6957
Fax: (714) 528 2338
Email: info@currieenterprises.com
1480 North Tustin Avenue
Anaheim, CA 92807
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