Our FJ40’s 11 year life span as a product test mule has officially ended. We celebrated its life with a few cold libations, said a few words and then threw some dirt on it memorializing its past existence. Its days of having hundreds of goodies bolted and welded to it have finally come to an end. Just moments after our eulogy, it was reborn as a would-be hard-core, dedicated trail rig,
ready to be stretched to a new wheel base with a 4-link suspension.
We needed something that would hold up to our 400+ HP fuelie motor that was recently transplanted, give us awesome articulation, better stability and a better departure angle. Sure, we could have done the math and built our own 4-link, but frankly I don’t have time or the cash and besides, Project In Too Deep (the little, green CJ5) is currently being converted to a custom home-grown 4-link so this will make for a great compare-and-contrast when it’s all said and done. While our FJ-40 will never be truly finished, we are fairly confident that the rear suspension will live out the rest of its years in its new configuration.
The four-link suspension is arguably the best of all worlds whether it is for hot rods, drag racers and certainly 4×4’s. For the 4-wheel drive enthusiast, it offers unparalleled suspension articulation, little to no axle wrap, if done correctly and needed adjustability as it relates to axle alignment and caster too. What’s more, it can be configured with several types of springs – air bags, coil-over shocks, air springs, and in our case coil springs with shock absorbers.
So what’s better than a 4-link suspension you might ask? A kit-form 4-link that you can install yourself – here’s why;
1) You don’t have to do all of the math and risk setting up the geometry all wrong – wasting time and money, getting flex-steer, incorrect anti-squat
2) You get the pride of building it yourself
3) You know that it’s done right
When I made the decision to convert from leaf springs to a 4-link, I knew there was only one company I could trust to provide the best 4-link do-it-yourself kit, and that’s Proffitt’s Cruisers in Austin, Colorado. Jeremiah Proffitt and his crew are Land Cruiser geniuses and the undisputed champions when it comes to building custom Land Cruisers and making top shelf products. Moreover, their products are well engineered and affordable – a combination that we are all looking for.
Proffitt’s 4-Link Coil Spring Conversion Kit
Proffitt’s Cruisers has two 4-link kits available for your FJ40; a bracket-only kit, and a full 4-link kit. The bracket-only kit comes with all of the necessary brackets for the frame and axle, plus an axle truss, heim joints, bushing rod-ends, threaded inserts, and full instructions. You provide the DOM tubing for the links, but you can also add lower coil over shock mounts or their complete spring bucket system for coil springs for an extra few bucks. Proffitt’s offers custom quarter elliptic spring capture tubes as well.
We chose the full 4-link kit for our project as we have a custom-built Ford 9” rear axle, and we wanted to stretch our wheelbase further than most, pushing the back of the rear tire to be nearly even with the back of the body. With the full Proffitt’s Cruisers 4-link kit, you get all of the items mentioned above, plus all 4 links are pre-made for your specified wheel base.
|Installation – Proffitt’s Cruisers 4-Link Suspension
||3-4 Days (for your average DIY)
||Welder, plasma cutter (optional, but highly effective) / torch, drill, drill bits, Full assortment of ratchets and wrenches, measuring tape, hammer, adjustable wrench, center punch, brake line wrenches, right-angle grinder, multiple magnetic angle finders, torque wrench, etc. For the most part, you’ll need a very good assortment of tools and a high degree of patience. This is by no means a bolt on kit, but with some careful measuring and a solid plan of attack this kit can be installed in a weekend.
||Note: This is a time-consuming job and is not recommended for the novice. Experienced welding skills are needed.
As with any project, take stock of the parts you have and the parts you need. Our Proffitt’s kit came with all of the weld-on / bolt-on parts that we needed, including bushings, heim joints, tabs, spring buckets, nuts, bolts and more. This is a VERY good 4-link kit and the craftsmanship is top-shelf.
Next, we needed to remove the rear suspension (leaf springs, spring hangers, etc.). Our FJ’s rear suspension (aside from the lift) is in stock form – meaning that the spring is under the axle. Secure the axle with jackstands (use three of them – two under the axle tubes and one under the pinion). Be sure your vehicle is secure! You will be wrenching on it and laying underneath it quite a bit. Now, begin disconnecting the driveshaft, emergency brake cable and brake lines. Lastly, remove the U-Bolts that hold the leaf spring to the axle.