Custom Lift and Suspension - Front Setup

Front - FabTech Dirt Logic 2.5 adjustable coilovers

OK, now here's the most difficult part of the suspension build. As I mentioned in the background, I decided to go with adjustable FabTech coilovers because of 2 reasons:

• potential droop in the front due to 200+ lbs of bumper and winch
• potential accelerated shock wear and tear also due to the weight and the upwards mass of the 33" tires

All the way back to last year, I had this set of coilovers in mind:

These were for a 2005 Jeep ZJ. As you can see, they looked promising because of the upper mount and how it would potentially fit into our mounting cup. But more important was their bottom mounting, and how it looked like it could work with our stock strut towers (which wrap around the front CV axles).

Problem was that month upon month, I could not get any measurement data on them. Not from FabTech directly, or through my contact at North Shore Offroad. Well time was running out for my trip to Colorado so I took a BIG chance and just ordered them.

And then the worst thing that could happen, happened. I got word back from NSOR that this model was discontinued. In fact, there were never any built, other than a prototype. They decided that there was not a big enough market for them so they cancelled the program.

So I started scouring the catalog, the web site, any source I could get my hands on for a potential alternative. What jumped out at me was the FTS2500K 0"-3.5" adjustable coilover system for the Toyota Tacoma and 4Runner. The thing that sold me was the instruction manual they had online which had a very accurate technical drawing. Knowing that the width of the shock body was 2.5", I could use Photoshop and extrapolate all the other measurements.

From this I could be quite certain that the spring diameter could work, that the mounting plate could fit inside our cups, and that the length was workable. The only thing that had me worried was how to mount the bottom of the coilover to the strut tower. Well, time was still running out so I decided to just go for it!

While I was waiting for the order to come in, I used this great used parts locator and bought 2 strut assemblies locally. After removing the struts I cleaned up the towers and got them powder coated blue to match the FabTech parts. And here are all the pieces next to each other for comparison.

And some close ups on the coilovers.

As you can see, the build quality of these parts is outstanding. However, the problem I was afraid of, came to pass. The diameter of the bottom coilover mounting point was larger than the inside diameter of the strut tower. I thought about getting something fabricated that would slip inside the strut tower (and get pinched by it) and provide a pin mount that would be above the strut tower. However, this would increase the effective length of the coilover by a couple of inches. Plus I was not comfortable with changing the engineering of our suspension by making the bottom mount a swivel-type mount instead of how it is stock, i.e. firmly attached to the tower.

This is where I looked to the professionals at National4WD for help. After showing all this to Ryan at the shop, he said he had some ideas but had to talk to a person he regularly used at a machine shop and get some feedback from him. After a few days Ryan called me in and showed me the proposed solution:

• The coilover would be inserted into the tower all the way up to the bottom of the spring cup (see picture above). This would pinch not only the spherical ball area, but also the small lip at the very top which is the full diameter of the mount.
  
  
• To accommodate this, the inside of the tower would be machined and the inside diameter expanded.
  
  
• The spherical ball openings would be oriented facing forward/back, to clear the bolt that partially passes through the strut mount.
  
  
• Then for added support/safety, he would machine 2 aluminum "half-moon" inserts, joined with a bolt that actually goes through the spherical ball mount (hidden) to "fill in" the space that is part of the coilover mount design, which allows the strut tower to pinch not only at the top (where the Fabtech is round) but all the way down to the bottom of the strut mount.

So there it is. The coilover was adjusted with the bumper and winch weight to give 2.5" of lift. Anything more would probably give rise to serious CV axle binding. As I wrote in other posts, the entire vehicle has been given vigorous work outs in my mini expedition around Georgian Bay, and then on the big one to Colorado.

Again, I can't say enough about the FabTech DirtLogic shocks. Absolutely first rate. The mounting solution that Ryan came up with has been rock-solid. There does not seem to be an issue with the suspension at full extension, even though the unsprung length of the FabTech coilovers seems to be a bit longer than stock. I guess time will tell ...