Explorer ProComp Coil Spring Suspension Lift kit for Jeep Wrangler YJ

Bolt on Coil Springs for a Wrangler (YJ)

Explorer Pro-Comps Coil YJ Spring Conversion & Lift Kit

Short Cuts

by: Bryan Archambeault

Page 2

Following the instructions, we first measured the front pinion angle with all the weight on the suspension.

We did not have an angle finder, so we used a level and a protractor. This was obviously not the correct way to find this angle, but it worked for us. Plus, the kit uses cams for the upper control arm mounts, so we figured we could always adjust it later it we were off a little.

Continuing with the instructions, we jacked up the front and put it on jack stands, and installed the front brake line kit. This went pretty smooth, although the factory mounting position in the wheel well is kind of hard to get to, even from inside the engine compartment.

Next we removed the front wheels, steering stabilizer, and shocks. We were supposed to remove the front track bar and sway bar at this point, but I had taken those off my vehicle a long time ago. You do not need a sway bar with this kit, but since this is a coil spring setup, you obviously need the track bar, so I had to go find it in my garage.

Next we removed the drivers side leaf springs, u-bolts, and u-bolt plate. Using an air wrench and a breaker bar, all these items came off very easily, although we did have to use a little WD-40 on the u-bolt nuts. The next step was to install the driver's side brackets. This is where we made our only mistake. The diagram of this step says to install the "Large Front U-Bolt" on one side of the bracket, and the "Small Front U-Bolt" on the other. There are 8 u-bolts included in the kit. 4 are 4.5" long, 4 are 6" long (2 of which are 3" wide, and 2 are 3.3" wide). If we would have compared the parts list with the diagram (which we did with all other steps), we would have seen that the "small" front u-bolts were smaller in width, not length. But, we assumed the diagram meant the 4.5" u-bolts were the small ones and proceeded to destroy 2 u-bolt nuts trying to get them to go on the front. Then, we went and bought 4 new 6" u-bolts thinking they had given us the wrong parts in the kit. Once we got to the rear installation, we figured out our error. Well, at least I've got 4 extra 6" u-bolts now!

The front bracket installation consists of securing the u-bolts and drilling two 3/8" holes in the spring perch. Make sure to center the holes, or the bolts won't go through correctly.

Next was to assemble the lower control arm. Since all the 4 lower control arms are the same, we went ahead and assembled them all at this point to have less parts laying around. Make sure to to put the 9/16" ID sleeve on the frame mount side and the 1/2" ID sleeve on the bracket mount side. And, ID does not stand for Identification, it stands for Inner Diameter. Could have saved myself a tech support call with that one. It doesn't mention it in the instructions, but we had to bend the leaf spring mount just a little where the lower control arms mount to get the arm in there with the spacers provided in the kit. Once it's in and torqued down, it comes right back together.


Grinding the shock mount	After Grinding

Next is to notch the upper shock mount in preparation for the upper coil bracket. For a "bolt-on" kit, this is the most non-bolt-in step. The instructions say "remove material as needed", so we just kept grinding off the corner of the shock mount until the bracket fit. Then you have to drill holes through the frame for the bracket. The two holes on the outside were easy, but the holes on the inside were tough as we could not get at them from the inside with the drill. We ended up using a small drill bit to go through the back of the frame from the front, and then enlarging it with bigger bits if we didn't get the small one exactly centered.


Front drivers side	Front drivers side from another angle	Front passenger control arms

Next you assemble the upper control arm. Again, we assembled all 4 arms to reduce parts. Next we did the passenger's side, which was exactly the same as the driver's side except for the bolt that the steering stabilizer mounts to. You don't have to drill a hole there since it already exists. Next we raised the front axle so that we could mount the upper control arms to the frame.


The track bar relocation bracket	Coils installed on the front drivers side	Front passenger side coils installed

We were supposed to install the drop pitman arm at the point. However, we could not get it off, so we proceeded with the instructions and put on the front track bar relocation bracket. Then we installed the front coils and shocks (the kit includes Pro-Comp ES9000s), and returned the vehicle to the ground. It sure looked funny with all that lift in the front and nothing in the back!


Front installed

We then raised and supported the rear of the vehicle and removed the brake lines, shocks, leaf springs, and drive shaft, and the removed the rear end from the Jeep. We put the new rear end that I was swapping in on a big wooden box, and installed the brackets and u-bolts there.


Bryan's brother gets the brackets on...	while Bryan installs the U-Bolts.	The rear bracket bolted in place.

It was much, much easier doing the work on the axle while we were standing up! The only part we had trouble with in the rear was the installation of the track bar relocation bracket. The instructions do not tell you, and the diagram is not clear, but one of the brackets actually goes inside of the stock track bar mount. The other part of the rear install that was not mentioned in the instructions was that our top brackets didn't quite fit inside the spring perches, so we needed to grind the corners off to get them to fit. Also, the bolts included in the kit that come through the bottom bracket, through the spring perch, and into the top bracket were not long enough. We bought some that were about 1/2" longer and they worked great.

We also had to grind off some material in the rear as we had done in the front. After we were done installing the brackets, we installed the rear end under the vehicle.


Grinding on the rear...	...and the frame after grinding	Bryan measures carefully for the bracket position

The rest of the rear end installation was just like the front and soon we had all 4 wheels on the ground.


Rear drivers side	Rear passenger side

With the kit installed and all weight on the new suspension, the front was sitting about 6" higher, and the back about 5" higher.


The front end before	The front end after	The rear end before	The rear end after

We then took our new 33x12.50 BFGs down and had them mounted and balanced, and once we installed them on the Jeep, the front was sitting about 7" higher, and the back about 6"

The front end with 33" tires installed.

At this point we removed the transfer case and installed the Advance Adapters fixed yoke kit [See the SYE article here]. Next we drained and refilled the transmission, and remounted the transfer case and refilled it. At that point, we measured the distance from the new C.V. yoke on the transfer case to the yoke on the rear differential (16 1/2" in my case) and ordered a top-of-the-line drive shaft from Tom Woods. I was borrowing a pitman arm puller from a friend of mine, and he needed it back one day while I was at work. He came over to get it, noticed my pitman arm was still installed, and proceeded to get it out for me. I have no idea how he did it. He said it took a lot of torque and a lot of banging on the puller with a big hammer. That's exactly what I had done, but he obviously has better technique than me! So, I installed the drop pitman arm, and reconnected the drag link. Later, we bled the brakes, put new bushings in the track bars and reinstalled them, and reinstalled the front drive shaft and drove the Jeep around the block in front wheel drive for the first time in three weeks! The new rear drive shaft arrived a couple of days later and we installed it right away. The suspension rides great. It is definitely better than stock. I have not come across any driveline vibrations at any speed or driving situation yet, so I have not had to adjust the cams on the upper control arms. I drove it to a field near my house that has some big mounds of dirt, and played around a little, but it was not a good test of my new offroad capabilities.


The finished lift.	The added steering stabilizer

The instructions do not mention that the steering stabilizer is not reused. I called about this and they told me that there is no provision for a steering stabilizer with this kit. However, the day after my new rear drive shaft arrived and I had driven on the freeway for the first time, a box from Explorer Pro-Comp arrived at my house with a new steering stabilizer and mounting kit. How's that for timing (and great customer service)!

Update - November 1, 1999 - After my Rubicon trip, my rear coils were sagging pretty bad. I called Pro-Comp, and they sent me out a full new set of coils (I had to send them my original ones back)! Now, my Jeep sits level and the highway ride is even better!

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